EXAMINATION OF THE SAFETY AND TEMPERATURE CHARACTERISTICS OF THE ALIMED® ICE FINGER^M

By

LORA CATHERINE SELBY, B.S.

A THESIS

IN

COMMUNICATION DISORDERS

Submitted to the Graduate Faculty of Texas Tech University Health Sciences Center

In Partial Fulfillment of the Requirements for the Degree of

MASTER OF SCIENCE

fl^

COMMUNICATION DISORDERS

Approved

May 2002

Copyright 2002, Lora Catherine Selby

ACKNOWLEDGEMENTS

There are several individuals I would like to thank who helped me complete this project. First of all, I would like to extend my deepest gratitude to Dr. Renee Bogschutz. Without her expert knowledge and unwavering faith, this project would have never taken flight. I would also like to thank Jermifer Hanners for her tireless efforts in supplying needed materials. I would like to extend my gratefulness to the remaining members of my committee, Dr. Rajinder Koul and Mary Beth Schmitt, for their support and expertise. I would also like to thank Lori Rice-Spearmann, program director for the Department of Clinical Lab Sciences, for providing the lab resources necessary to complete this project. Further, I would like to thank the faculty of the Department of Communication Disorders for their support. Lastly, I would like to extend many thanks to Kasey, Matthew, and my family. Without their constant assurance and encouragement I would have never had the strength to finish.

TABLE OF CONTENTS

Page ACKNOWLEDGEMENTS ii

ABSTRACT v

LIST OF TABLES vn

LIST OF FIGURES viii

CHAPTER

I. INTRODUCTION AND REVIEW OF LITERATURE 1

Introduction 1 Dysphagia 2

Definition 2 Risk Factors, Signs, and Symptoms of Dysphagia 3 Incidence of Dysphagia 4 Delayed Pharyngeal Swallow Reflex 5

Neurophysiology of Swallowing 5 Normal Swallowing 5 Pharyngeal Swallow Reflex 7

Pharyngeal Muscle Activity 8 Muscles of the Soft Palate 9 Muscles of the Pharynx 9 Extrinsic Muscles of the Larynx 10 Intrinsic Muscles of the Larynx 11

Pharyngeal Sensory Input 12 Thermal Stimulation 15

Classic Thermal Stimulation 15 Limitations to Classic Thermal Stimulation 18 Advantages of the Ice FingerT"^ Device 19 Ice Finger^"^ Disadvantages 21

Dysphagia Treatment Efficacy 23 Purpose 24 Conclusion and Rationale 24

111

IL METHODS 26

Experimental Design 26 Materials 26 Procedures 27

Experiment 1 27 Experiment 2 31 Experiment 3 34 Experiment 4 39

Data Analysis 40 Measurement Reliability 41 Data Entry 41

m. RESULTS 43

Introduction 43 Experiment 1 43 Experiment 2 47 Experiment 3 52 Experiment 4 56

IV. DISCUSSION 57

Introduction 57 Safety Characteristics 57 Safety Limitations 60 Temperature Characteristics 62 Miscellaneous Observations 64 Conclusion 65

REFERENCES 67

ABSTRACT

Thermal stimulation is a common clinical technique used in the treatment of

dysphagia. Historically, a cold laryngeal mirror, or other type of cold probe, was used to

stroke one or both of the anterior faucial pillars several times prior to the swallow.

Recently, a new device, the AliMed® Ice Finger^M, was introduced for thermal

stimulation, which offered the swallowing therapist a better-constructed device that

allowed for more flexibility during thermal stimulation.

The purpose of this bench study was to report safety and temperature data

regarding the AliMed® Ice Finger™, as this type of data does not yet exist. This type of

research was important as it may aid swallowing therapists, commonly speech-language

pathologists, in making judgments regarding the safety of their patients when using the

Ice FingerTM. This data was also important because it would aid in determining which

thermal stimulation device holds cold temperature across a significant period of time.

Four major experiments were carried out to determine the safety and temperature

characteristics of the AliMed® Ice Finger''''^. Durability was measured across varying

temperature conditions, sites of force application, and cleaning methodologies. Cold

temperature retention was measured across varying storage methodologies. The

sterilization properties of the Ice Finger^M were also determined by culturing various Ice

Fingers'" ' from three different cleaning methods.

Out of 260 Ice FingersT"^ tested for durability, 3 ruptured (i.e., one included in the

solid frozen group at Pi and two included in the repeated use group cleaned with mild

detergent). Ice Fingers^"^ stored in a cup of ice retained the coldest temperatures for a

longer period of time, but Ice Fingers^"^ in all three temperature storage conditions stayed

below body temperature and in the range of oral cold receptor stimulation. None of the

fifteen cultured Ice Fingers'^'^ from the three different cleaning methodologies

demonstrated any growth, even after 48 hours.

The results of this study indicated that the Ice Finger M was a safe and durable

device for use in the management of dysphagia patients. The results also indicated that

the Ice Finger''''^ retained cold temperatures sufficient for stimulating cold receptors

during thermal stimulation.

VI

LIST OF TABLES

Table Page 1. Listing of MadaCide-FD Germicidal Solution active ingredients 32

2. Results from ambient, regular frozen, and solid frozen Ice FingersTM included in Experiment 1A for P] 44

3. Results from ambient, regular frozen, and solid frozen Ice FingersT"^ included in Experiment 1A for P2 46

4. Results from ambient, regular frozen, and solid frozen Ice Fingers^M included in Experiment IB for distributed force 47

5. Results of frozen Ice Fingers^"^ for single cleaning with a mild detergent included in Experiment 2A 48

6. Results of frozen Ice Fingers^*^ included in Experiment 2B, single cleaning with a germicidal solution 49

7. Results of frozen Ice Fingers'^'^ in the repeated use condition cleaned with a mild detergent included in Experiment 2C 50

8. Results of frozen Ice Fingers^"^ in the repeated use condition cleaned with a germicidal solution included in Experiment 2D 51

9. The mean temperature and standard deviation per time interval for Ice Fingers'^^ stored at body, ambient, and ice temperature 53

10. The average temperature change and the average change in degrees per change in time interval for Ice Fingers^'^ stored at body, ambient, and ice temperature 54

11. The results of culturing Ice Fingers^"^ over three conditions: MC) MadaCide-FD, MD) mild detergent, and OP) out of package 56

Vll

LIST OF FIGURES

Figure Page 1. Pharyngeal Swallow Reflex Arch 15

2. Pi measured as Vi the distance of the Ice Finger™ casing in Experiment 1 A... 28

3. P2 measured as VA of the casing length, as measured from the terminal end in Experiment lA 28

4. The distributed force setup, which was used for Experiment IB 30

5. Ice Fingers^"^ were submerged in MadaCide-FD for 10 minutes during Experiments 2C and 2D 32

6. A 200 g weight was suspended at the mid point of the Ice Finger M during the thawing process for Experiments 2C and 2D 33

7. The components of an Ice Finger^M include: A) external black handle, B) white plastic ring, and C) internal black handle. The line at " 1 " indicates the scissor cut site needed to remove the white plastic ring and the extra casing.... 36

8. Acu-Rite digital thermometers, one inserted into the Ice Finger M and the other in the heated water, are shown for Experiment 3A 37

9. Two digital thermometers, one inserted into the frozen Ice Finger^"^ and the other positioned in the mug away from the Ice Finger^'^, are shown for Experiment 3B 38

10. Two digital thermometers, one inserted into the Ice Finger^^ and the other positioned in the mug away from the Ice Finger^" , are shown for Experiment 3C 39

11. A 50 ml centrifuge tube is depicted, which was used to transport Ice Fingers^"^ during Experiment 4 40

12. This picture shows the terminal end rupture for Ice FingerT^ #5, included in Experiment 1A 45

Vll l

13. This picture shows the terminal end rupture for Ice Finger^"^ #3, included in Experiment 2C 50

14. This picture shows the medial seam rupture for Ice Finger^'^ #12, included in Experiment 2C 51

15. The change in the temperature over time of Ice Fingers^"^ stored at body temperature (warm water), ambient temperature, and in a cup of ice 53

16. Ice Fingers^^ used in this study varied in size 64

17. Ice FingerTM A depicts the "bubbly" appearance as compared to Ice Finger M B, which is clear in appearance 65

18. Ice Finger^M A depicts a protruding end as compared to Ice Finger M B, which has a flat end 65

CHAPTER I

Introduction and Review of the Literature

Introduction

Clinical practice and research related to swallowing disorders is a growing field.

The clinical management of swallowing disorders dates back to the 1930's (Huckabee &

Pelletier, 1999), but it has only been since the 1980's that the corpus of knowledge

regarding the treatment of swallowing disorders has increased (Mills, 2000). The

research regarding swallowing disorders has also grown over the years, moving from

"anecdotal accounts of therapeutic successes to well-designed clinical research articles"

(Miller & Langmore, 1994). There continues to remain a need, though, for more research

on the efficacy and safety of treatments for swallowing disorders (Miller & Langmore,

1994).

Often a team approach to the treatment of swallowing disorders is taken, in which

a variety of professionals are involved in the treatment process. It was noted by

Rosenbeck, in the foreward of Huckabee and Pelletier's (1999) Management of Adult

Neurogenic Dysphagia, that the practice of swallowing disorders is interdisciplinary due

to the fact that "swallowing and swallowing disorders are complex." Therefore the

management of these swallowing disorders is also complex. Professionals such as

gastroenterologists, neurologists, pulmonologists, respiratory therapists, dietitians,

pharmacists, occupational therapists, and speech-language pathologists may all play a

key role in the management of swallowing disorders (Logemann, 1998).

Speech-language pathologists are often the primary swallowing therapists. The

speech-language pathologist completes a case history of the patient's and/or family's

complaints regarding swallowing. The initial evaluation is conducted and appropriate

treatment strategies are introduced by the speech-language pathologist (Logemann,

1998). The speech-language pathologist is then presented with a host of swallowing

therapy techniques and materials to review with the patient and their family. Speech-

language pathologists should be informed as to which swallowing therapy techniques and

devices are the safest and most appropriate for each patient, based on valid clinical data.

In addition, data regarding devices used during swallowing therapy should also be

available to speech-language therapists when choosing an appropriate treatment protocol.

Dysphagia

Definition

Dysphagia is typically defined as difficulty moving food, liquids, or pills from the

mouth to the stomach (Logemann, 1998; Murry & Carrau, 2001). Swallowing occurs in

four different stages or phases: the oral preparatory stage, the oral stage, the pharyngeal

stage, and the esophageal stage. During the first stage, the oral preparatory stage, food or

liquids placed in the oral cavity are prepared or masticated. The food, or bolus, is then

moved posteriorly by the tongue toward the pharynx. The pharyngeal swallow reflex is

triggered during the pharyngeal phase and the bolus is moved through the esophagus to

the stomach during the esophageal stage (Logemann, 1998). Swallowing difficulties

during any one of these stages can negatively impact the quality of life, as well as the

psychological well being of patients with dysphagia. In other words, food not only

sustains biological functions but is also related to social and familial interactions and

activities.

Risk Factors, Signs, and Svmptoms of Dysphagia

There are a range of risk factors, signs, and symptoms associated with dysphagia.

Risk factors cause a person, or a group of people, to be vulnerable to unwanted or

unhealthful events. Probably the most common risk factor of dysphagia is aspiration.

Logemann (1998) defined aspiration as "the entry of food or liquid into the airway below

the true vocal folds." Aspiration can occur before, during, or after a swallow. Another

risk factor of dysphagia is penetration. Penetration is the entry of food or liquid into the

larynx, but above the level of the true vocal folds. Other risk factors associated with

dysphagia include residue and backflow. Residue is food left behind in the oral or

pharyngeal cavities following a swallow, while backflow is the movement of food from

the esophagus and/or the pharynx into the pharynx and/or nasal cavity (Logemann,

1998). These four risk factors can potentially cause aspiration pneumonia, a sign and

complication of dysphagia.

Conversely, signs are objective findings identified by a professional. Signs related

to dysphagia are defined through objective measures and include delayed pharyngeal

swallow reflex, weight loss without any other explanation, and a gurgly or wet sounding

voice.

Symptoms are subjective indicators of dysphagia perceived by patients

themselves. Symptoms include patient complaints of coughing during meals or the

inability to control food in the oral cavity. Patients may present with one or more of the

risk factors, signs, or symptoms that are commonly observed with a diagnosis of

dysphagia (Logemann, 1998).

Incidence of Dysphagia

Populations that have a high incidence of dysphagia typically present with either

structural abnormalities or neurological insults. Structtaral abnormalities or neurological

causes of dysphagia can be genetic, congenital, or developmental in nature. Structural

abnormalities "may result from trauma, surgery, tumors, caustic injury, or congenital

conditions" (Gelfand & Richter, 1989). For example, head and neck cancer can result in

structural abnormalities. Tumors may decrease tissue pliability, block nerves necessary

for swallowing, or obstruct mechanical structures involved in swallowing (Murry &

Carrau, 2001). The treatments involved in cancer rehabilitation can also increase a

patient's risk for dysphagia. Chemotherapy, radiation, and surgery can all cause

difficulties that can disrupt the normal swallowing pattern (Murry & Carrau, 2001).

Individuals presenting with dysphagia as a result of neurological insults may

demonstrate a peripheral or central nervous system lesion of the neurological pathways

involved in swallowing. These neurological insults may include not only acute injuries,

such as stroke or traumatic brain injury, but also degenerative diseases, such as

Parkinson's disease or multiple sclerosis (Periman & Schulze-Delrieu, 1997; Groher,

1997). These patient populations associated with neurologically based dysphagia

commonly present with a delayed pharyngeal swallow and/or a weak swallow (Miller &

Langmore, 1994).

Delayed Pharyngeal Swallow Reflex

As just mentioned, one sign of dysphagia is a delayed pharyngeal swallow reflex,

which occurs during the pharyngeal stage of swallowing. For individuals with a normal

swallowing pattern, the swallow reflex takes approximately 1 second (Gelfand & Richter,

1989), but for those individuals with a delayed pharyngeal swallow (e.g., patient with

neurological damage), the onset of the swallow reflex takes longer. Before the delayed

swallow is triggered there is a greater risk of aspiration and penetration since food,

especially thin liquids, may penetrate the pharyngeal and laryngeal cavities while the

airway remains open (Logemann, 1998). The cause of such a delay has been linked to

sensory deficits in which "inadequate sensory feedback mechanisms fail to communicate

the oncoming bolus" to the pathways responsible for triggering the swallow reflex

(Huckabee & Pelletier, 1999). As such, it stands to reason that increased sensory

awareness may be targeted during swallowing therapy specifically designed to heighten

awareness in the oral and pharyngeal cavities.

Neurophysiology of Swallowing

Normal Swallowing

To gain a better understanding of disordered swallowing, swallowing therapists

should posses knowledge of the neurophysiology of normal swallowing. This knowledge

can assist the swallowing therapist in making accurate decisions regarding treatment

protocols based on each patient's dysphagia symptoms.

As previously stated, the process of swallowing occurs in four main stages: the

oral preparatory stage, oral stage, pharyngeal stage, and esophageal stage. During the oral

preparatory stage, food is masticated in preparation for swallowing. The airway is open

during the oral preparatory stage, reinforcing the need for oral bolus control (Logemann,

1998). The oral stage is described as a voluntary phase (Gelfand & Richter, 1989) in

which the bolus is moved posteriorly by the tongue to the pharynx (Groher, 1997). The

tongue tip lifts, pressing the bolus against the hard palate creating pressure gradients

within the oral cavity to help propel the bolus towards the pharynx (Logemann, 1998).

The central groove of the tongue then acts as a passageway for the bolus to be propelled

posteriorly towards the pharynx (Gelfand & Richter, 1989).

The third stage of swallowing, the pharyngeal stage, follows the oral preparatory

and the oral stages of swallowing. Several motor actions take place during the pharyngeal

stage, which is considered to be an involuntary, or reflexive, stage of swallow patterning

(Murry & Carrau, 2001). As the head of the bolus reaches the pharynx, the nasopharynx

is closed off by elevation and retraction of the velum, which prevents the bolus from

entering the nasal cavity (Gelfand & Richter, 1989). Elevation and anterior movement of

the larynx and the hyoid bone then contribute to adequate closure of the laryngeal

vestibule. The ventricular and true vocal folds adduct to further protect the airway

(Logemann, 1998). At this point, respiration ceases to prevent the bolus from entering

the airway, and the pharyngeal constrictor muscles contract to aid in the propulsion of the

bolus fi-om the pharynx to the opening of the esophagus (Groher, 1997). The upper

esophageal sphincter (UES) relaxes and opens, allowing the bolus entrance into the

esophagus. Following the pharyngeal stage, the esophageal stage begins with the bolus

entering the upper esophageal sphincter. Peristaltic action then pushes the bolus from the

upper esophageal sphincter to the opening of the stomach (Logemann, 1998).

Pharyngeal Swallow Reflex

The neurophysiology of swallowing has been determined through various

methods of data collection. These methods include electromyography, lesioning, and/or

the removal of muscles thought to play key roles during swallowing events. In an attempt

to determine the nature of swallowing neurophysiology, the timing and electrical activity

of muscles have been recorded using electromyography (EMG). Researchers have also

lesioned areas of the central and peripheral nervous systems or removed specific muscles

and/or muscle groups to stiidy swallow pattems in an animal model (Miller, 1986).

Through this type of research there is a consensus that the pharyngeal stage of

swallowing is indeed reflexive, due to the consistent sequential timing of sensory and

motor activities. These reflexive activities are thought to be controlled by a central

swallowing pathway, swallowing pattem generator (Miller, 1999), which is contained

within the brainstem region (Periman, 1991). Therefore, stimulation of certain brainstem

nuclei can evoke swallowing. The specific areas of the brainstem that evoke reflexive

swallowing include the dorsal area of the reticular formation "around and partially

including the nucleus tractus solitarius" and the "ventral region of the reticular formation

around the nucleus ambiguus" (Miller, 1986). The nucleus ambiguus is thought to

primarily initiate the motor portion of the pharyngeal swallowing reflex (Logemann,

1998).

It is also possible to evoke the swallowing reflex through stimulation of

peripheral nerve and ganglion fields. For example, the posterior tongue and the

oropharyngeal region, which are sensory innervated by the pharyngeal branches of

Cranial Nerve (CN) IX and/or by the superior or recurrent laryngeal nerve of CN X, can

be stimulated to evoke swallowing (Miller, 1986). These sensory fibers synapse in the

nucleus tt-actiis solati-ius (Miller, 1986) as well as the nearby reticular formation of the

dorsal region of the medulla (Miller, 1999). The sequential timing of specific motor

events will be dispersed to the appropriate cranial nerve nuclei, or in some species to the

ventral region of the reticular formation that includes the nucleus ambiguus. From these

areas muscles involved in the pharyngeal swallow will be stimulated, and the sequential

timing of motor events during the pharyngeal swallow will take place (Miller, 1999).

The reflexive theory of the pharyngeal swallow has been criticized based on

clinical findings and anecdotal reports. More specifically, insults to the cortex or

subcortex have been linked to dysphagia. In fact, the swallowing pathway of the

brainstem may be integrated with regions of the cortex that "activate and control" the

swallowing stages (Miller, 1999). However, it has been shown that these regions of the

cortex are not necessary for the swallowing reflex to occur (Miller, 1986).

Pharyngeal Muscle Activity

Motor activity to the oropharynx during the pharyngeal phase of swallowing is

primarily controlled by the following cranial nerves: the trigeminal nerve (CN V), the

facial nerve (CN VII), the glossopharyngeal nerve (CN IX), the vagus nerve (CN X), and

the hypoglossal nerve (CN XII). The spinal nerve segments CI to C3 also play a role in

pharyngeal muscle innervation (Kahrilas, 1993).

Muscles of the Soft Palate

The two muscles involved in velar elevation are the levator veli palatini and the

musculus uvulae. Both of these muscles are innervated by the pharyngeal plexus, which

is formed by fibers from the pharyngeal branches of CN IX, X, and XI (Netter, 1991).

Muscles anatomically positioned to lower the velum include the palatopharyngeus

and the palatoglossus. According to Seikel, King, and Drumright (1997), the

palatopharyngeus lowers the soft palate and narrows the pharyngeal cavity. The

palatopharyngeus is innervated by the pharyngeal plexus (Seikel, King, & Drumright,

1997). The palatoglossus, which is also innervated by the pharyngeal plexus, is

anatomically positioned to lower the soft palate (Periman, 1991). It has also been

postulated that palatal lowering may be due to relaxation of the levator veli palatini

muscle, which allows the tissue of the soft palate to return to resting position via passive

forces (Goodrich & Hall, 1995).

Muscles of the Pharynx

Three important pharyngeal elevators/dilators include the stylopharyngeus, the

palatopharyngeus, and the salpingopharyngeus muscles. The stylopharyngeus muscle is

innervated by the muscular branch of CN IX and, upon contraction, elevates the pharynx.

The palatopharyngeus, innervated by CN X and the spinal accessory nerve via the

pharyngeal plexus, dilates the pharynx. The salpingopharyngeus muscle is also

innervated by CN X and CN XI via the pharyngeal plexus and elevates the lateral

pharyngeal wall (Seikel, King, & Drumright, 1997).

The superior, medial, and inferior constrictors aid in transporting the bolus

through the pharynx to the opening of the esophagus by narrowing, or sequentially

contracting, the pharynx as the bolus passes through the ttibe. These muscles are

innervated by CN X and CN XI via the pharyngeal plexus (Periman, 1991).

Extrinsic Muscles of the Larynx

The muscles commonly referred to as the suprahyoid muscles include the

thyrohyoid, mylohyoid, anterior belly of digastric, posterior belly of digastric, stylohyoid,

geniohyoid, hyoglossus, and genioglossus muscles (Seikel, King, & Drumright, 1997).

The thyrohyoid muscle elevates the thyroid cartilage and is innervated by CN XII

(Periman, 1991). The mylohyoid and the anterior belly of digastric muscles elevate the

hyoid bone and are both innervated by the inferior alveolar branch of CN V (Periman,

1991). The posterior belly of digastric and the stylohyoid muscles also elevate the hyoid

bone. The posterior belly of digastric is innervated by the digastric and the motor branch

of CN VII, while the stylohyoid muscle is innervated by the motor branch of CN VII

(Seikel, King, & Drumright, 1997). The geniohyoid muscle elevates and draws the hyoid

bone forward (Seikel, King, & Drumright, 1997) and is innervated by CN XII (Periman,

1991). The hyoglossus and the genioglossus muscles, though considered muscles of the

tongue, are involved in hyoid bone elevation when the tongue is fixed. Both muscles are

innervated by the motor branch of CN XII (Seikel, King, & Drumright, 1997).

The four muscles that lower the hyoid bone are the sternohyoid, the superior and

inferior bellies of the omohyoid, the sternothyroid, and the thyrohyoid muscles. These

muscles are commonly referred to as the infrahyoid muscles. The sternohyoid is

innervated by the ansa cervicalis, which arises from the spinal nerve segments CI to C3

(Seikel, King, & Drumright, 1997). The omohyoid muscle is also innervated by the spinal

nerve segments CI to C3. The sternothyroid is innervated by spinal nerves CI and C2

10

that travel with the CN XII nerve (Seikel, King, & Drumright, 1997). The thryohyoid is

innervated by the spinal nerve segment CI, which converges with CN XII (Seikel, King,

& Drumright, 1997).

Intrinsic Muscles of the Larynx

Vocal fold adduction and abduction occurs through motor stimulation of four

insti^nsic laryngeal muscles. The muscles of the larynx that aid in vocal fold adduction

include the lateral cricoarytenoid (Periman, 1991) and the oblique and transverse

interarytenoid muscles (Seikel, King, & Drumright, 1997). These muscles are all

innervated by the inferior branch of the recurrent laryngeal branch of CN X (Seikel,

King, & Drumright, 1997). The only muscle known to abduct the vocal folds is the

posterior cricoarytenoid muscle, which is innervated by the recurrent laryngeal branch of

CN X (Seikel, King, & Drumright, 1997).

Tensors and relaxers of the vocal folds include the cricothyroid and the

thyrovocalis and thryomuscularis muscles (two masses of the thyroarytenoid muscle).

The thyrovocalis is a vocal fold tensor and is innervated by the recurrent laryngeal branch

of CN X. The cricothyroid is a vocal fold tensor and is iimervated by the external branch

of the superior laryngeal nerve arising from CN X. Conversely, the thyromuscularis is a

vocal fold relaxer and is innervated by the recurrent laryngeal branch of CN X (Seikel,

King, & Drumright, 1997).

11

Pharyngeal Sensory Input

The cranial nerves primarily involved in sensory innervation during the

pharyngeal swallow reflex include the trigeminal nerve (CN V), the glossopharyngeal

nerve (CN IX), and the vagus nerve (CN X).

The maxillary and mandibular branches of CN V provide the sensory innervation

to the oral and pharyngeal regions (Miller, 1999). The maxillary branch innervates the

velum, whereas the mandibular branch innervates the faucial pillars. A majority of the

tiigeminal sensory fibers synapse in either the principal trigeminal nucleus or the spinal

ti-igeminal nucleus, but afferent sensory fibers from the oral cavity project to all

ti-igeminal sensory nuclei, which also includes the mesencephalic tiigeminal nucleus

(Miller, 1999). Fibers from the principal trigeminal nucleus and the spinal trigeminal

nucleus then project to the thalamus (Miller, 1999). More pertinent to swallowing, it has

been noted that sensory fibers from the trigeminal nerve also synapse with the nucleus

tractus solitarius, which receives sensory input and integrates said input with several

reflexes, including the pharyngeal swallow (Miller, 1999).

Cranial nerve IX receives sensory information from the velum, posterior tongue,

and pharynx (Miller, 1999). The majority of glossopharyngeal sensory fibers synapse in

the nucleus tractus solitarius (Miller, 1999).

The sensory fibers of the pharyngeal, superior laryngeal, and recurrent laryngeal

branches of CN X receive sensory information from the pharyngeal and laryngeal regions

(Seikel, King, & Drumright). The pharyngeal branch detects sensory information from

the base of the tongue and the upper pharynx. The superior laryngeal branch, also called

the superior laryngeal nerve, receives sensory information from the laryngeal mucosa

12

above the vocal folds, while the recun-ent laryngeal branch senses the laryngeal mucosa

below the level of the vocal folds (Seikel, King, & Drumright). Sensory fibers of CN X

synapse in the nucleus tractiis solitarius (Miller, 1999).

Sensory receptors in the oral cavity, pharynx, and larynx provide sensory

information during each stage of swallowing. Specialized receptors not only detect touch,

chemicals, and taste, but temperature as well (Miller, 1999). Touch and pressure sensory

receptors are referred to as mechanoreceptors. There is a greater density of

mechanoreceptors located on the tongue, but touch and pressure stimuli are also received

from other areas, including the hard palate, the periodontium, and areas of the pharyngeal

and laryngeal regions (Miller, 1999). Mechanoreceptors discriminate bite force, the size

and shape of a bolus, and have been linked to "protective reflexes that prevent aspiration"

(Miller, 1999). Sensory receptors that react to specific chemicals, such as water, saline,

dextrose, and carbon dioxide are located throughout the oral cavity, pharynx, and larynx

(Miller, 1999). Certain areas of the oral and pharyngeal cavities are more sensitive to

specific tastes. For example, the dorsal tongue surface senses salt and sweet better,

whereas the palate senses sour and bitter more effectively. The pharynx is not as sensitive

in sensing sah, sweet, sour, and bitter (Miller, 1999).

Temperature receptors are located in specialized temperature-sensitive sites

throughout the oral cavity. Temperature-sensitive sites exist for both cold and warm

temperatures, but a greater number of cold sites exist as compared to warm sites (Miller,

1999). This is a major basis of the use of cold probes during thermal stimulation, a

commonly used therapy technique. When a cold stimulus is applied to a cold receptor

site, the cold sensation increases the firing rate of the sensory nerve fiber detecting

13

sensation from that particular region (Miller, 1999). Conversely, when a warm stimulus

is applied to a cold site, the firing rate of the sensory nerve decreases (Miller, 1999).

It has been hypothesized that cold-sensitive receptors are present in the anterior

faucial pillars (Kaatzke-McDonald, Post, & Davis, 1996). Similariy, the anterior faucial

pillars have also been identified as one of the most sensitive areas in eliciting the swallow

reflex (Pommerenke, 1928). This is why thermal stimulation used to heighten sensory

awareness in the oral cavity is most often done on the anterior faucial pillars. Afferent

information fi-om the mucous membrane of the anterior faucial pillars is carried by the

CN IX (Periman, 1991). These afferent fibers enter the nucleus tractus solitarius, and

"numerous projections are sent to the reticular formation" (Periman, 1991), which is a

part of the central swallowing pathway.

In summary, the pharyngeal swallow reflex is characterized by a sequence of

events, as shown by Figure 1, that occur in a time-locked fashion in individuals with

normal swallowing pattems. Sensory input from the oral and pharyngeal cavities is sent

to the sensory nuclei of the brainstem, which in turn activates the motor nuclei in the

brainstem for CNs V, VII, IX, X, and XII. These cranial nerves then activate muscles

involved in the swallow reflex.

14

Brainstem Nuclei - Sensory

Principal Trigeminal Nucleus Spinal Trigeminal Nucleus

Mesencephalic Trigeminal Nucleus Nucleus Tractus Solitarius

Brainstem Nuclei - Motor

Masticator Nucleus Motor Nucleus of CN VII

Hypoglossal Nucleus Nucleus Ambiguus

Dorsal Vagal Nucleus

Sensory Input

Cranial Nerve V Cranial Nerve IX Cranial Nerve X

Motor Output

Cranial Nerve V Cranial Nerve VII Cranial Nerve IX Cranial Nerve X

Cranial Nerve XII Spinal Segments C1-C3

Figure L Pharyngeal swallow reflex arch.

Thermal Stimulation

Classic Thermal Stimulation

As stated, thermal stimulation is a common clinical technique used in the

treatment of dysphagia. A cold laryngeal mirror, or other type of cold probe, is used to

stroke one or both of the anterior faucial pillars several times prior to the swallow

(Logemann, 1998; Bove, Mansson, & Eliasson, 1998; Rosenbeck, Robbins, Fishback, &

Levine, 1991; Rosenbeck, et al., 1998; Rosenbeck, Roecker, Wood, & Robbins, 1996;

Selinger, Prescott, 8c McKinley, 1990; Lazzara, Lazarus, & Logemann, 1986; Kaatzke-

McDonald, Post, & Davis, 1996; Hanners, J. & Powell, K., 2000; Groher, 1997; Chemey,

15

1994; Huckabee & Pelletier, 1999). The anterior faucial pillars are targeted as they are

the most sensitive areas to thermal stimulation due to the concentration of cold-sensitive

receptors on the anterior faucial pillars (Kaatzke-McDonald, Post, & Davis, 1996).

According to Logemann (1998), thermal stimulation heightens awareness in the

oral cavity. It also serves as a sensory stimulus that alerts the brainstem to initiate a

reflexive swallow. Consequently, this type of sensory input affects the contraction of

muscles and the threshold at which a swallow is triggered (Miller, 1999). As such,

thermal stimulation given prior to the initiation of a swallow has been shown to trigger

the pharyngeal swallow reflex more quickly (Logemann, 1998). Thermal stimulation has

been recommended for individuals demonstrating delayed triggering of the pharyngeal

swallow, mild to moderate dysphagia, and other oral sensory deficiencies (Logemann,

1998; Rosenbeck, Robbins, Fishback, & Levine, 1996).

Studies have been conducted to investigate the effects of thermal stimulation.

Lazzara, Lazarus, and Logemann (1986) conducted a study involving 25 neurologically

impaired adults demonstrating a delay in triggering a swallow. Each subject was given

two swallows each of 1/3 teaspoon of barium liquid and 1/3 teaspoon of barium paste.

Following the presentation of each consistency, thermal stimulation was performed and a

third bolus of the same consistency was given. The total transit time was reduced in 82%

of patients given a liquid consistency and 100% of patients given a paste consistency.

Thermal stimulation produced immediate effects that lasted for two to three subsequent

swallows (Lazzara, Lazarus, & Logemann, 1986).

Rosenbeck, Roecker, Wood, and Robbins (1996) conducted a sttidy involving 23

adults with histories of multiple sfi-okes. Subjects were given 10 untreated swallows of a

16

semi-solid bolus followed by 10 swallows, each one preceded by thermal stimulation.

Duration of stage ti-ansition (i.e., time between the bolus reaching the posterior margin of

the ramus of the mandible and elevation of the hyoid as seen in lateral video flouroscopy)

and total swallow duration were reduced in treated swallows as compared to untreated

swallows (Rosenbeck, Roecker, Wood, & Robbins, 1996).

Further, in a stiidy involving 10 healthy female subjects, cold touch to the anterior

faucial pillars produced a higher percentage of swallow responses as compared to just

touch or placebo stimulation (Kaatzke-McDonald, Post, & Davis, 1996).

Today thermal stimulation is widely used among clinicians in the field of speech-

language pathology (Rosenbeck, Roecker, Wood, & Robbins, 1996), but it is a technique

that remains controversial among researchers. For example, in a study by Bove,

Mansson, and Eliasson (1998), 14 healthy subjects were given thermal stimulation and

then asked to hold cold water in their mouth prior to performing the Repeated Dry

Swallow Test (i.e., swallow 11 times as quickly as possible) (Bove, Mansson, &

Eliasson, 1998). The researchers concluded that neither technique significantly affected

swallowing rate in healthy subjects. Another study, in which 14 healthy subjects received

thermal stimulation prior to swallowing, revealed no significant changes in the timing of

treated swallows versus untreated swallows. In justification of the results, the authors of

this study hypothesized that the "healthy swallow is primed for minimal oral-pharyngeal

latency and cannot be improved upon" (Ali, Laundl, & Wallace, 1996). It may also be the

case that healthy subjects may not be appropriate subjects for thermal stimulation

research due to normal sensory innervation.

17

Selinger, Prescott, and McKinley (1990) sttidied the effects of thermal stimulation

on a 56-year-old male, 3 months after a brainstem stroke. Thermal stimulation was given

over 9 days, for a total of 26 trials. The subject continued to aspirate after 9 days of

treatment. The authors noted that thermal stimulation is recommended as a "long-term

intensive treatinent," and that 9 days may not have been enough time to see optimum

results. Additionally, the subject participating in the study demonstrated an absent rather

than a delayed swallow reflex. According to the article, the subject also lacked

pharyngeal sensation, therefore, may not have been an ideal candidate for thermal

stimulation.

Rosenbeck, Robbins, Fishback, and Levine (1996) studied 7 males with histories

of multiple strokes resulting in dysphagia over a 1-month period. Subjects were either

given thermal stimulation treatment or a non-treatment. The authors concluded that there

was no significant evidence that thermal stimulation improved swallowing in dysphagic

individuals following multiple strokes, but that there were some immediate changes in

swallowing physiology directly following the presentation of thermal stimulation. The

authors hypothesized that thermal stimulation may be more appropriate for individuals

demonstrating mild to moderate deficits rather than moderate to severe deficits.

Limitations to Classic Thermal Stimulation

Research has provided sufficient evidence that the use of thermal stimulation in

the treatment of dysphagia has statistically significant effects on swallowing physiology

in humans (Rosenbeck, et al., 1998; Rosenbeck, Roecker, Wood, & Robbins, 1996;

Lazzara, Lazarus, & Logemann, 1986; Kaatzke-McDonald, Post, & Davis, 1996).

18

However, clinicians in the field have cominued to find some fiinctional and/or clinical

limitations to devices currently used in thermal stimulation.

The success of thermal stimulation therapy is often reliant on the patient's ability

to follow commands. Patients who experience neurological damage, such as an acute

sti-oke, often demonstrate difficulty with voluntary motor control and/or following

commands. For example, voluntarily opening their mouths may be slow and difficult

(Logemann, 1998).

To combat this limitation, the ice glove was devised as a way to facilitate thermal

stimulation in cognitively impaired patients. The ice glove was a technique in which a

latex glove was filled with water, such that when frozen, the fingers were filled with solid

projections of ice. The clinician then used one of the ice-filled fingers to perform thermal

stimulation. For the cognitively impaired patient who had difficulty following directions,

the clinician could rub one of the ice-filled fingers on the patient's cheek to facilitate a

mouth opening response. The clinician could also use his/her little finger to part the

patient's lips, penetrate the buccal cavity, and then gently pull forward and insert the ice

glove into the buccal cavity. Over time clinicians found limitations to the ice glove,

including allergic reactions to the latex material and the cumbersome design of the ice

glove. For example, while performing thermal stimulation, the clinician needed to keep

the remaining four fingers of the ice glove away from the patient's face.

Advantages of the Ice Finger™ Device

Recently, a new device was introduced for thermal stimulation use. This new

device, the Ice Finger™, offered the clinician a better-constructed device that allowed for

more flexibility during thermal stimulation. This flexibility was perpetuated by the

19

advanced design of the Ice Finger^", which eliminated the need to constantly displace the

extra fingers of the ice glove. Similar to the ice glove, while using the Ice Finger™ for

thermal stimulation, the clinician could use his/her little finger to part the patient's lips to

allow the Ice Finger' ' entrance into the buccal cavity. The Ice Finger^" could also be

rubbed against the patient's lips and cheeks to "evoke a mouth opening response."

An advantage of the Ice Finger^"^, put forth by the manufacturer, was an ability to

hold cold temperatures for a longer time. Cold thermal stimulation has been found to be

most effective when the mucosal temperature is decreased to between 20°C and 34.5°C,

the range in which cold receptors are most sensitive (Kaatzke-McDonald, Post, & Davis,

1996). It has been noted in the literature that a chilled laryngeal mirror begins to warm

quickly when removed from ice (Kaatzke-McDonald, Post, & Davis, 1996). According to

the user's manual, the Ice Finger" '* is filled with a malleable substance that can sustain

cold temperature for 15 to 20 minutes after being frozen (Hanners, J. & Powell, K.,

2000). Unfortunately, there is no empirical evidence to support this claim or define the

temperature characteristics of the Ice FingerT^ over time.

Based on the neurophysiology of swallowing and the existence of sensory

receptors, specifically cold receptors, in the oral and pharyngeal cavities, it has been

proposed that thermal stimulation is an effective technique in the treatment of dysphagia.

Not only is thermal stimulation thought to be effective, it is also widely used by

swallowing therapists around the country. The Ice Finger™ offers swallowing therapists a

more flexible design when working with neurologically impaired patients, whereas the

procedure for using a laryngeal mirror requires that a patient demonstrate relatively intact

voluntary motor control and the ability to follow commands. Determining which

20

procedural device is better and safer in the treatment of dysphagia may allow swallowing

therapists to better serve their patients requiring this form of therapy.

Ice Finger™ Disadvantages

Although the Ice Finger^M was created to combat the disadvantages of earlier

devices used in thermal stimulation, potential disadvantages may still exist. However,

there is no clinical or experimental data to validate the possible disadvantages of the Ice

FingerTM.

According to the "Directions for Application, Use and Care" sheet provided with

each package of AliMed® Ice Fingers ' , the Ice FingerT^ is not recommended for use

with tonic bite reflex, for those who cannot maintain adequate oxygen saturation levels

(90-100%), and/or for individuals presenting with bradychardia or tachycardia (AliMed®

inc., 2001).

A tonic bite reflex is a "forcefiil or tense biting pattem that interferes with all

aspects of feeding" (Nicolosi, Harryman, & Kresheck, 1996). The tonic bite reflex has

also been described by Logemarm (1998) as an abnormal oral reflex that may occur in

conjunction with neurologic impairments. Abnormal, or pathologic reflexes, are related

to lesions of upper motor neurons and are "normally suppressed by cerebral inhibition"

(Chusid, 1985). The pathological tonic bite reflex may be elicited through stimulation of

the teeth or gums, making it difficult for a patient to open his/her mouth during sustained

muscle contraction (Nicolosi, Harryman, & Kresheck, 1996). This difficulty opening the

mouth is most likely due to the magnitude of bite force upon elicitation of the tonic bite

reflex.

21

in

mean

Ranges of bite force for tonic bite reflexes in adults are not currently available i

the research literattire. However, a wide range of voluntary bite force has been

documented for normal adult subjects. According to Clark and Carter (1985), the

maximum voluntary bite force of 10 normal males was 36,080 (± 7400) g. In another

sttidy estimating incisal bite forces, the authors reported variability in maximum bite-

force across 10 subjects. Bite force ranged fi-om 4,000 to 40,000 g when the mouth was

opened to 15 mm and 2,500 to 30,000 g when the mouth was opened to 30 mm (Gay,

Rendell, Majoureau, & Maloney, 1994). Unforttinately, the extent to which voluntary bite

force and the bite force generated reflexively are similar is unknown.

The Ice FingerTw is not currently recommended for use with patients

demonsti-ating a tonic bite reflex; however, no data exists regarding the amount of force

required to mpture the Ice FingerTM. This sttidy will attempt to report data conceming the

safety and use of the Ice Finger^"^ with patients demonstrating a tonic bite reflex.

According to the "Directions for Application, Use and Care" sheet provided with

each package of AliMed® Ice Fingers^'^, the Ice Finger^^ should be cleaned before the

first use (AliMed® inc., 2001). Hand washing the Ice Finger™ with mild detergent and

then rinsing to remove residue is recommended. Following use, it is suggested that the

Ice Finger''''* be rinsed, stored in a sterile container, and re-frozen to be used with the

same client. However, the "Directions for Application, Use and Care" do not recommend

a specific sterile container in which to store the Ice Finger^" . To date there is no

evidence to support this type of cleaning methodology and associated patient safety

issues.

22

Even though there are many recommendations for Ice FingerTM use, there is no

clinical evidence to support these recommendations. For example, it has been

recommended that the Ice FingerTM be cleaned with mild detergent instead of using a

sterilizing agent, yet there is not data to support this suggestion. It has also been

recommended that the Ice FingerTM not be used with individuals demonstrating a tonic

bite reflex, and again, there is no data to support this recommendation.

Dysphagia Treatment Efficacy

The efficacy of dysphagia treatment has greatly evolved in the last 20 years.

Greater attention has been given to "well-designed clinical research articles" (Miller &

Langmore, 1994) to gain information regarding successful treatment of dysphagia.

Treatment techniques that have been used for years by swallowing therapists have been

justified by sufficient evidence regarding their effects on the anatomy and physiology of

swallowing. In addition to effects on anatomy and physiology, the safety of treatment

techniques, as well as the safety of the devices used in the techniques, should be explored

to ensure overall patient safety. New technological advances are constantly being made

in the field of dysphagia ti-eatment, such as the devices used in ti-eatment. Technological

advances have also been instrumental in providing evidence of ti-eatment efficacy.

Unforttinately, despite an increase in the number and type of efficacy sttidies available,

certain dysphagia management techniques and devices remain controversial (Miller &

Langmore, 1994) and call for more controlled research data.

23

Purpose

The purpose of this study is to report safety and temperature data for the Ice

Finger"^^. This data will include the amount of force required to rupture the Ice Finger' ' ,

the ability to use sterilization fluid instead of mild detergent, and the effect of using

sterilization fluid on the amount of force required to rupture the Ice Finger^M. The

sterilization properties of the Ice Finger^"^ over three conditions will be reported, as well

as temperature data, such as the amount of time the Ice Finger "^ will retain cold

temperature in different storage environments.

Speech-language pathologists should always consider patient safety and the

adequacy of therapy techniques when choosing an intervention protocol in the treatment

of dysphagia. Data collected during this sttidy may assist speech-language pathologists in

making informed decisions regarding the safety and the temperature retention

characteristics of the AliMed® Ice FingerTM.

Conclusion and Rationale

In summary, dysphagia affects a wide range of individuals and is associated with

various symptoms. A delayed swallow reflex can result in symptoms such as aspiration,

due to the fact that the airway remains open when food or liquid falls into the pharynx

(Logeman, 1998). These symptoms can negatively impact a person's health, as well as

his/her social and familial roles.

Thermal stimulation is a treatmem commonly recommended for individuals

demonstrating a delayed pharyngeal swallow reflex (Logemann, 1998) because it

increases sensory inpm to the brainstem, which in ttim activates the muscles involved in

24

pharyngeal swallowing more quickly. Classically, thermal stimulation is performed using

an iced laryngeal mirror, but swallowing therapists have realized the limitations of this

procedure and have explored other options for the delivery of dysphagia management in

the form of thermal stimulation. The ice glove technique has been used for cognitively

impaired patients, as well as other special populations of dysphagia patients, but the

design of the device has lead to other difficulties. The Ice Finger™ was devised to

alleviate design difficulties and provide swallowing therapists with a clinical tool that

would not only be safer and more efficient, but easier to use with patients with

dysphagia. However, to date, there is no data regarding the safety and temperature

characteristics of the Ice Finger™. Therefore, the data collected for this study aided in

answering the following research questions:

1. For various resting temperatures, can the Ice Finger "^ be ruptured with the

application of site specific or evenly distributed force?

2. With single and repeated use and cleaning (mild detergent or germicidal solution),

can the Ice Finger^M be mptured with the application of force?

3. What is the best storage methodology for Ice FingerTM cold temperattire

maintenance?

4. Based on cleaning methodology, what are the sterilization properties of the Ice

FingerTM?

25

CHAPTER II

Methods

Experimental Design

This study was a bench study that reported safety and temperature data regarding

the AliMed® Ice Finger^"^. Four experiments were conducted to determine force of

mpture over various conditions, as well as cold retention properties, as this type of data

does not yet exist for the Ice Finger^'^.

Materials

The following materials were used to complete this study:

335 AliMed® Ice FingersTM GE Select Refrigerator/Freezer

Pieces of wooden board (avg. size 19.6 X GE Energry Saver Refrigerator/Freezer 2.45X1.475 cm) Lengths of Lehigh seine twine (60cm or 30 Panasonic microwave cm) Ohaus gram weights, two sets totaling4200 g Bessey adjustable clamp

One Citmed sterile tongue depressor Manco masking tape

Extra Value zipper plastic sandwich bags Staedtler Lumocolor permanent pens

Ecko refrigerator/freezer thermometer Plastic metric mler

Two Acu-Rite digital instant read Pampered Chef measuring cup thermometers Gateway VX920 Computer Ceramic mug

Microsoft Excel software Ivory® liquid soap in a 7.5 oz pump

StatView software MadaCide-FD Germicidal Solution

Sigma Plot software Cocktail ice

26

Procedures

Experiment 1

The first research question of Ice Finger™ durability was answered using three

conditions of varying temperatures: ambiem (22° C), regular frozen (frozen at -20° C),

and solid fi-ozen (frozen at -30° C). These temperattire conditions were chosen to

determine the safety or durability of the Ice FingerTM when frozen at different

temperatiires or at resting ambient temperattire. Ice Fingers^M in the regular frozen group

were fi-ozen in a GE Select refrigerator-freezer, while solid frozen Ice FingersTM were

frozen in a GE Energy Saver refrigerator freezer. Ice Fingers' ' in the solid frozen

condition were iced to -30° C in the GE Energy Saver freezer as the GE Select fi-eezer

had a limited temperature variation range and was being maintained at -20° C for Ice

Fingers^'^ in the regular frozen condition. An Ekco refrigerator/freezer thermometer was

constantly used to monitor the temperature within each refrigerator-freezer. While the Ice

FingersT"^ were frozen, they were stored in Extra Value zipper plastic sandwich baggies

to avoid any contact with Ice Fingers^** used in different experiments or other items

stored in the freezers. Following either freezing or storage at ambient temperature,

durability of the Ice Fingers^M was measured at two specific points on the Ice FingerTM

(Experiment 1 A) or as distributed force was applied (ExperimentIB).

Experiment lA: Specific Points - Two site specific points were chosen for this

procedure: point one (Pi) was operationalized as Vi of the total length of each Ice

FingerTM casing, and point two (P2) was operationalized as % of the casing length, as

measured from the terminal end of each Ice FingerTw. Figure 2 depicts force application

at Pi, while Figure 3 depicts force application at P2. Pi and P2 were selected as site

27

is specific poims for force application based on recommendations for clinical use. It

recommended that patients suck on the Ice Finger™, therefore P, and P2 were considered

logical bite points, due to the clinical placemem of the Ice Finger™ in the oral cavity.

Figure 2. Pi was measured as Vi the distance of the Ice Finger™ casing.

Figure 3. P2 was measured as Vi of the casing length, as measured from the terminal end.

Sixty Ice Fingers''"' (20 per each of 3 temperature conditions: ambient, regular

frozen, and solid fi-ozen) were selected for force application at Pi and sixty additional Ice

FingersTM were selected for force application at P2. Application points. Pi or P2, were

measured with a plastic metric mler and marked on the casing of each individual Ice

FingerTM with a Staedtler Lumocolor permanent pen. Following random Ice Finger™

selection and group allocation, the extemal handle of each Ice Finger™ was secured to a

piece of board (avg. size 19.6 X 2.45 X 1.475 cm) with Manco masking tape when the

handle was lined up flush with the edge of the bench. The piece of wooden board was

then secured to the bench with a Bessey adjustable clamp.

28

Ohaus gram weights were then suspended from either P, or P2 with a length of

Lehigh nylon seine twine (60 cm) tied into a loop. Gram weights were applied until

which time the Ice FingerTM rupttired upon visual inspection or a total of 4200 g had been

applied. A gram weight application paradigm was established for all mpttire experiments

based on pilot experiments. Gram weights were applied in increments of 500 g up to a

total of 2500 g. Gram weights were then applied in increments of 100 g up to a total of

3500 g. Finally, gram weight increments of 50 g were applied until all weights had been

exhausted for a total of 4200 g.

Gram weight increments were applied approximately every other minute

following a visual inspection of the Ice FingerT" casing. After each increment of weight

was applied, the Ice FingerT^ was visually inspected for casing mpture. Casing mpture

was operationally defined as any visible crack or tear in the plastic casing of the Ice

Finger^M and/or visual evidence of a mpture such as leaking of the internal gel material.

Following exhaustion of gram weight application, regular and solid frozen Ice Fingers™

were also visually inspected for casing mpture after a complete thaw, several hours

following completion of the experiment.

Experiment IB: Disfi-ibuted Force - Distributed force was applied to Ice

FingersTM of varying temperatures with a Citmed sterile tongue depressor, 15cm in length

and 1.7 cm in width, was ti-immed to 7.5 cm in length and 1.5 cm in width and then

wrapped with two layers of Manco masking tape. The tongue depressor was taped to

smooth the surface and potentially prevent any casing puncttire due to wood splinters.

Three notches were cut into each side of the tongue depressor, 1 cm from each end and at

the mid point. Notches were made to secure the nylon twine in place across presentations.

29

ace Three lengths of Lehigh nylon seine twine (30 cm) were tied imo loops and taped in pi

at each pair of notches, which served to immobilize the loops of Lehigh seine twine. The

inferior loose ends of the three loops were gathered and taped together with a small piece

of Manco masking tape. Figure 4 illustrates the tongue depressor and string settip, which

was developed to evenly disti-ibute the gram weight across the Ice Finger™ casing.

Figure 4. The distributed force setup, which was used for Experiment IB.

The extemal handle of each Ice Finger''"' was secured to a piece of board with

masking tape so that the handle was flush with the edge of the bench. The wooden board

was then secured to the bench with a Bessey adjustable clamp. The Citmed tongue

depressor and strings were placed on the superior surface of the Ice Finger M casing,

without overlapping the extemal handle, as seen in Figure 4.

Following Ice Finger™ preparation, Ohaus gram weights were suspended fi-om

the gathered loops of Lehigh seine twine in sequential order. Gram weights were applied

using the same weight application paradigm described in the previous section. Gram

weight placement was continued until there was a visible sign of mpttire or all gram

weights had been exhausted. After each increment of weight was applied, the Ice

FingerTM was visually inspected for casing mpttire as previously defined.

30

Experiment 2

The second research question explored the durability of single and multiple use of

frozen Ice Fingers^M cleaned by one of two different methodologies. Experiments 2A and

2B addressed the durability of single use Ice FingersTM cleaned with either a mild

detergent or a germicidal solution. Experiments 2C and 2D related to multiple use Ice

Finger M durability with either the mild detergent or germicidal solution cleaning

methodologies.

Experiment 2A: Single Cleaning - Twenty Ice Fingers^M were cleaned once with

a mild detergent. Ivory® soap, and then frozen (-20° C) in a GE Select freezer. Following

removal from the freezer, the extemal handle of each Ice Finger M was secured to a piece

of board with Manco masking tape, such that the handle was flush with the edge of the

bench. The wooden board was then secured to the bench with a Bessey adjustable clamp.

Ohaus gram weights were then consecutively suspended from the mid point of each Ice

Finger M with a length of Lehigh nylon seine twine (30 cm) tied into a loop. Again, the

same gram weight application paradigm, as previously described, was used until a casing

mpttire was observed or all weight increments were exhausted.

Experiment 2R: Single Sterilization - The procedure for Experiment 2B was

exactly the same as Experiment 2 A with the exception of the utilized cleaning method.

For this experiment 20 Ice Fingers™ were cleaned with MadaCide-FD Germicidal

Solution and then frozen one time. Table 1 lists the active ingrediems included in

MadaCide-FD Germicidal Solution. MadaCide-FD is a germicidal solution used for

cleaning various surfaces, including plastic. The directions for use, located on the bottle,

followed when cleaning Ice Fingers™. The casing of each Ice Finger™ was were

31

submerged in MadaCide-FD for approximately 10 minutes. Figure 5 displays an Ice

FingerTM submerged in the germicidal solution. During submersion, each Ice Finger™

was placed in a metal, cylindrical container filled with enough MadaCide-FD to

completely cover the Ice FingerT^ casing, while avoiding the handle area. Following 10

minutes of submersion, the Ice Finger™ was removed fi-om the container and placed on a

paper towel to air-dry, as per bottle instmctions. Each Ice Finger™ was then frozen and

the procedure continued as described in Experiment 2A.

Active Ingredients

N-Alkyl (68%)Ci2, 32%)Ci4) dimethyl ehylbenzyl ammonium chloride N-Alkyl (60%Ci4, 30%Ci6, 5%Ci2, 5%Cig) dimethyl benzyl ammonium chloride Isopropanol

% Concentration

0.154%

0.154%

21.000%

Table 1. This table lists the active ingredients of MadaCide-FD Germicidal Solution, as displayed on the bottle.

Figure 5. Ice Fingers™ were submerged in MadaCide-FD for 10 minutes during Experiments 2C and 2D.

32

Experiment 2C: Repeated Cleaning - Twenty Ice Fingers™ were frozen (-20° C)

for at least 6 hours at a time in a GE Select fi-eezer, thawed, and cleaned with a mild

detergent (Ivory® soap) for a total of 10 consecutive times. During each thawing process,

the extemal handle of each Ice FingerTM was secured to a piece of board with Manco

masking tape, such that the inferior edge of the extemal handle was flush with the edge of

the bench. A length of Lehigh nylon seine twine (60 cm) was tied into a loop and

positioned at the midpoint of the Ice Finger^'^ casing as measured by a mler.

Approximately 200 g of weight was then applied for 1 hour to the loop of twine. Weight

was thus applied during thawing in an attempt to replicate repeated use over time. Figure

6 depicts the placement of the 200 g weight during the thawing process of Experiments

2C and 2D. The 200 g amount was chosen based on pilot experimentation in that the

weight application displaced the internal material and casing but did not cause casing

mpture.

Figure 6. A 200 g weight was suspended at the mid point of the Ice Finger™ during the thawing process for Experiments 2C and 2D.

33

Following a complete thaw, each Ice Finger™ was washed by hand using a small

amount (i.e., one pump) of liquid Ivory® hand soap and warm tap water. The soap was

worked into a lather and then each Ice FingerTM was hand washed for approximately 30

seconds and thoroughly rinsed with warm tap water. Ice FingersTM were then gently

dried with a clean paper towel and rettimed to the correct plastic zipper bag in the GE

select freezer.

Following 10 sessions of freezing, thawing, and cleaning, the Ice FingerTM was

made ready for the gram weight application paradigm by securing it to the piece of board

in the same fashion as previously discussed in Experiment 1. The gram weights were then

applied according to the gram weight paradigm until a visual mpture was observed or all

weights were exhausted.

Experiment 2D: Repeated Sterilization - Twenty Ice Fingers^"^ were frozen (-20°

C) in a GE Select fi-eezer for at least 6 hours, thawed, and sterilized with MadaCide-FD

Germicidal Solution for a total of 10 consecutive times. The same cleaning paradigm as

discussed in Experiment 2B was followed. Similar to Experiment 2C, during each

thawing process, a 200 g weight was applied to the mid point of each Ice FingerTM for 1

hour. Following 10 sessions of fi-eezing, thawing, and cleaning, the procedure continued

as described in Experiment 2C.

Experiment 3

The third research question related to the ability of the fi-ozen Ice FingerTM (frozen

at -20° C) to retain cold temperattire as measured over three conditions of varying storage

temperatures: water warmed to body temperattire, ambient temperature, and storage in

ice.

34

Experiment 3A: Body Temperattire - Twenty randomly selected Ice Fingers™,

frozen at -20° C, were used for this experimem. To begin this experiment, 300 ml of tap

water was measured in a plastic Pampered Chef measuring cup and then heated in a

Panasonic microwave for approximately 40 seconds. An Acu-Rite digital thermometer

was then immediately placed in the water after it was removed from the microwave. The

average temperattire of the water upon removal from the microwave was 40° C. The

water temperattire was monitored until it reached approximately 37.8° C (i.e., 0.8° above

body temperature), at which time an Ice FingerTw was removed from the freezer and

prepared for the experiment.

To prepare the Ice FingerTM, the extemal black handle of each Ice Finger M was

manually removed revealing the white plastic ring under the extemal handle. Scissors

were then used to cut off the white plastic ring and the portion of the Ice Finger M casing

located above the ring. The cut was made just inferior to the white plastic ring but

superior to the interior black handle. The interior black plastic handle, located directly

inferior to the white plastic ring, was then manually removed. Figure 7 depicts the

components of an Ice Finger^"^ as well as the cut needed to remove the interior black

handle and white plastic ring. An Acu-Rite digital thermometer was inserted into the

open, or serrated, end of each frozen Ice FingerT" , which was then placed in a standard

size ceramic mug. A piece of Manco masking tape, approximately 11 cm in length, was

taped to the mug and to the edge of the digital thermometer to allow the Ice FingerTw to

stand upright in the mug, which is depicted by Figure 8. This also prevented the heated

water from seeping into the top of the Ice FingerTw and warming it fi-om within.

35

Figure 7. The componems of an Ice Finger™ include: A) extemal black handle, B) white plastic nng, and C) imemal black handle. The line at " 1 " indicates the scissor cut site needed to remove the white plastic ring and the extra casing.

The first temperattire reading for the Ice FingerTM and the heated water was taken

3 minutes after the thermometer had been inserted into the Ice FingerTw, but prior to the

addition of the heated water to allow for thermometer temperattire stabilization. After 3

minutes, the heated water (average temperattire 37.005° C) was poured into the ceramic

mug containing the fi-ozen Ice FingerTM. An Acu-Rite digital thermometer was then

placed in the water and positioned so that it did not make contact with the Ice Finger™.

Temperature readings for both the Ice FingerTw and the water were taken every 10

minutes for a total of 6 temperature readings over 50 minutes. This procedure of pouring

the heated water into the mug after thermometer stabilization was used for this portion of

the Experiment 3A, as pilot data revealed rapid Ice Finger M warming during

thermometer stabilization. The following experiments (i.e., 3B and 3C) combine air and

ice with the Ice Finger'' ' during the 3-minute thermometer stabilization period.

36

Figure 8. Acu-Rite digital thermometers, one inserted into the Ice Finger™ and the other in the heated water, are shown for Experiment 3A.

Experiment 3B: Room Temperature - Twenty randomly selected Ice Fingers^M

frozen at -20° C were also used for this experiment. The Ice Fingers^^ were opened and

prepared for thermometer insertion as described in Experiment 3A. An Acu-Rite digital

thermometer was inserted into the open, or serrated, end of each fi-ozen Ice Finger^M. The

Ice Finger^^* was then placed in a standard size ceramic mug with the second Acurite

digital thermometer, positioned so that it did not make contact with the Ice Finger M in

order to obtain air temperature readings, which is depicted in Figure 9. The first

temperature reading was taken three minutes after the thermometer had been inserted into

the Ice Finger^"^ to allow for thermometer temperature stabilization. Temperature

readings were then taken every 10 minutes for a total of 6 temperature readings over 50

minutes.

37

Figure 9. Two digital thermometers, one inserted into frozen Ice Finger™ and the other positioned in the mug away from the Ice Finger™, are shown for Experiment 3B.

Experiment 3C: Ice - Twenty randomly selected Ice FingersTw frozen at -20° C

were also used for this experiment. Again, the Ice Fingers^M were opened and prepared

for thermometer insertion as described in Experiment 3 A. An Acu-Rite digital

thermometer was inserted into the open, or serrated, end of each frozen Ice FingerTM. The

Ice FingerT^* was then placed in a standard size ceramic mug with approximately 420 ml

of cocktail ice, which completely surrounded the Ice Finger^" . A second Acu-Rite digital

thermometer was placed into the mug, positioned so that it did not make contact with the

Ice Finger^"^. The placement of the digital thermometers is depicted in Figure 10. The

first temperature reading was taken 3 minutes after the thermometer had been inserted

into the Ice Finger^"^ to allow for thermometer temperature stabilization. Temperature

readings were then taken every 10 minutes for a total of 6 temperature readings over 50

minutes.

38

Figure 10. Two digital thermometers, one inserted into the Ice Finger™ and the other positioned in the mug away from the Ice Finger™, are shown for Experiment 3C.

Experiment 4

The fourth research question regarding the sterilization properties of the Ice

Finger'T' was answered by culturing various Ice Fingers^"^ from three different cleaning

methods (i.e., no cleaning, mild detergent, and germicidal solution). Fifteen Ice Fingers^M

were cultured by the Texas Tech University Health Sciences Center Department of

Clinical Lab Sciences. Culturing included five Ice Fingers™ taken directly from the

manufacturer's packaging, five Ice Fingers™ individually cleaned with a small amount

of Ivory® liquid soap as described in Experiment 2 A, and five Ice FingersTM cleaned

with MadaCide-FD germicidal solution according to the directions on the bottle as

described in Experiment 2B. Each Ice Finger™ was then placed into a 50 ml centiifiige

tube for transport to the lab. Figure 11 depicts a 50 ml centrifuge ttibe used in Experiment

4. Centi-ifiige ttibes were labeled with a Staedtler Lumocolor permanent pen according to

Ice FingerTM cleaning method and Ice FingerTw number.

39

Figure 11. A 50 ml centrifuge tube is depicted, which was used to transport Ice Fingers™ during Experiment 4.

Following transport to the lab, each specimen was plated onto a Blood Agar Plate

(BAP). A positive control. Staphylococcus epidermidis, and a negative control, sterile

water, were also plated onto BAP and incubated with the submitted specimens at 37

degrees Celsius in ambient air. The cultures were checked at 24 hours incubation and 48

hours incubation for the presence of any growth.

Data Analysis

Research question 1 - Descriptive statistics were used to report the results of any

casing mpture per force application by temperature condition. The dependent variable for

these experiments was mpture, while the independent variables were amount of weight,

point of weight application (specific force or evenly distributed force) and temperature of

Ice Finger^M (ambient, regular frozen, and solid frozen).

Research question 2 - Descriptive statistics were used to report the results of any

casing mpture per force application by experimental condition. The dependent variable

for these experiments was mpture, while the independent variables were amount of

weight, repeated or single use, and cleaning methodology.

Research question 3 - Descriptive statistics and graphical representations were

used to represent the temperattire characteristics of the Ice Fingers^M in each condition. A

40

3X6 repeated measures ANOVA, with conditions and temperattire as within subject

factors, was performed to determine significant differences between storage methods

(i.e., water warmed to body temperattire, ambient, and cup of ice) and time measurement

interval (i.e., six 10-minute intervals). If main effect was statistically significant, a post-

hoc measure was then performed to specifically determine any significant differences

between the storage methods. A priori significance was determined asp < 0.05.

Research question 4 - The lab findings from the Texas Tech University Health

Sciences Center Department of Clinical Lab Sciences were reported following culturing

of the Ice Fingers^^ for each condition.

Measurement Reliability

Interjudge reliability was determined by having a second trained judge record

measurements or presence/absence of Ice Finger M mpture, simultaneously with the

investigator for 10% of the measurements for each experiment. An interjudge reliability

coifficient of no less than 0.90 was accepted. Pearson r-values were 1.0 for both

simultaneous mpture analyses and temperature measurements.

Data Entry

Data was hand written by judges on prepared data sheets and then entered and

saved onto a Gateway VX920 computer using the spreadsheet program Microsoft Excel.

Data entry error was evaluated by having a second blinded judge review the data entiy

spread sheet with the hand written data sheets. All errors were corrected until there was

an exact match between bench measures and data entiy numeric values. Data was then

41

transferred to SigmaPlot and StatView for graphical depiction and statistical analysis,

repectively. Averages and means were calculated mathematically by Microsoft Excel,

resulting in no estimated mathematical calculation errors.

42

CHAPTER III

Results

Introduction

The purpose of this bench study was to report safety and temperature data

regarding the AliMed® Ice FingerTM, as this type of data does not yet exist. This type of

research was important as it may aid swallowing therapists, commonly speech-language

pathologists, in making judgments regarding the safety of their patients when using the

Ice Finger^"^. This data is also important because it would aid in determining which

thermal stimulation device holds cold temperature across a significant period of time.

Four major experiments were carried out to determine the safety and temperature

characteristics of the AliMed® Ice Finger M in Experiment 1, the durability of the Ice

Finger' ' was tested over varying temperatures. Weight was applied to Ice Fingers^"^ at

either two specific points or as distributed weight. Experiment 2 examined the durability

of the Ice FingerT^ for single and repeated use based on cleaning methodology. The third

experiment measured the cold retention properties of the Ice Finger M over three

conditions of varying storage temperatures. The fourth research question of sterilization

properties was answered through culttiring Ice Fingers^M across varying cleaning

methodologies.

Experiment 1

Experiment lA - Table 2 represents the state of mpttire (i.e., mpttire or non

mpttire) for Ice Fingers™ in each of the three temperattire conditions (i.e., ambient,

regular frozen, and solid frozen) at Pi. There was no presence of casing mpttire for any

Ice Finger^M i^ the ambient or regular frozen temperattire conditions. However, one Ice

43

Finger™ (number 5) mpttired in the solid frozen temperattire condition, as is shown in

Figure 12. Due to the small natiire of the mpttire, it was not visually detected until the Ice

Finger™ had thawed sufficiently to allow for leakage of the imemal gel material. In

summary, 59 of the 60 Ice Fingers™ used in this experimem sustained weight application

ofupto4200gatPi .

Assigned

Ice Finger^M

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

Ambient

Rupture No Rupture

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

Regular Frozen

Rupture No Rupture

4200 q

4200 g

4200 g

4200 q

4200 q

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

Solid Frozen

Rupture

4200 q

No Rupture

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

Table 2. Results from ambient, regular frozen, and solid frozen Ice Fingers' ' included Experiment lA for force application site Pi.

in

44

Figure 12. This picture shows the terminal end mpture for Ice Finger™ #5 included in Experiment lA.

Table 3 represents the state of mpture for Ice Fingers''''^ in each temperature

condition for weight placement site P2. None of the 60 tested Ice Fingers^"^ mptured with

weight application at P2. Regardless of Ice Finger M temperature, all Ice Fingers''''^

sustained weight application up to 4200 g.

45

Assigned

Ice Finger^M

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

Ambient

Rupture No Rupture

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

Regular Frozen

Rupture No Rupture

4200 q

4200 q

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

Solid Frozen

Rupture No Rupture

4200 g

4200 g

4200 g

4200 g

4200 g

4200 q

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

Table3. Results from ambient, regular frozen, and solid frozen Ice Fingers™ included Experiment lA for force application site P2.

in

Experiment IB - Table 4 represents the state of mpttire for Ice FingersTM in each

temperature condition for distributed weight placement. None of the 60 tested Ice

FingersTM ruptured with distributed weight application. To summarize, all Ice Fingers

sustained distributed weight application of up to 4200 g.

TM

46

Assigned

Ice

Finger^^

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

Ambient

Rupture No Rupture

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

Regular Frozen

Rupture No Rupture

4200 g

4200 g

4200 g

4200 q

4200 g

4200 g

4200 q

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

Solid Frozen

Rupture No Rupture

4200 q

4200 g

4200 g

4200 q

4200 q

4200 g

4200 g

4200 q

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

4200 g

Table 4, Results from ambient, regular frozen, and solid frozen Ice Fingers™ included in Experiment IB for distributed force application.

Experiment 2

Experiment 2A - Table 5 represents the state of mpture for single use Ice

FingersTM cleaned with a mild detergent. All 20 frozen Ice fingersT^ cleaned with a mild

detergent withstood 4200 g of weight application without mpturing.

47

Assigned Ice Sin; FingerTM Rupttire

8

10 11 12

Experiment;

13 14 15 16

Single Use - Mild Detergent tiire No Rupttire

_17 4200 g J 8 4200 g J 9 4200 g 20 Jl I 4200 g

Table 5. Results of frozen Ice Fingers' ' for single cleaning with a mild detergent Experiment 2A.

4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g

included in

Experiment 2B - Table 6 represents the state of mpttire for single use Ice

Fingers^'^ cleaned with a germicidal solution. Similar to the results of Experiment 2 A, all

20 frozen Ice FingersTw in this condition withstood 4200 g of weight application without

mpturing.

48

Assigned Ice Finger^'^

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

- '—' ' • 1 . . . J—

Single Use - Germicidal Solution Rupture No Rupture

4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g

Table 6. Results of frozen Ice Fingers " included in Experiment 2B, single cleaning with a germicidal solution.

Experiment 2C - Table 7 represents the state of mpttire for repeated use Ice

Fingers^"^ cleaned with a mild detergent. For this experiment 18 out of the 20 total Ice

FingersTM sustained gram weight application. Ice FingersTw #3 and #12 mpttired

following 4200 g of weight applied at the ice Finger mid point. Ice Finger™ #3, shown in

Figure 13, mptured at the Ice Finger™ terminal end, whereas Ice Finger™ #12, shown in

Figure 14, mpttired at the medial seam 0.5 cm below the extemal black handle. Rupture

was detected on both Ice FingersT " following a complete thaw, which allowed for visible

leakage of the intemal material.

49

Assigned Ice Finger^M

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Repeated Use -Rupture

4200 g

4200 g

Mild Detergent No Rupture 4200 g 4200 g

4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g

4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g

Table 7. Results of frozen Ice Fingers'^'^ in the repeated use condition cleaned with a mild detergent included in Experiment 2C.

Figure 13. This picttire shows the terminal end mpture for Ice Finger™ #3, included in Experiment 2C.

50

Figure 14. This picttire shows the medial seam mpttire for Ice Finger™ #12, included in Experiment 2C.

Experiment 2D - Table 8 represents the state of mpture for repeated use Ice

Fingers™ cleaned with a germicidal solution. All 20 frozen repeated use Ice Fingers™

cleaned with a germicidal solution were able to withstand 4200 g of weight application

without mpturing.

4

Assigned Ice Repeated Use - Germicidal Solution Finger^M Rupture | No Rupture

II I 4200 g 4200 g 4200 g

6

8

10 11 12 13 14 15 16 17 18 19 20

Table 8. Resu ts of frozen Ice Fingers M in solution included in Experiment 2D.

4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g 4200 g

I 4200 g II the repeated use condition cleaned with a germicidal

51

Experiment 3

Experimems 3A through 3C focused on the temperattire characteristics of the

AliMed® Ice Finger™ per storage methodology (i.e., body, ambiem, and ice

temperattire). Results were described per experiment and statistically analyzed using a 3

X 6 (Storage Method x Time Measurement Interval) repeated measures ANOVA, with the

change in Ice FingerTw temperattire as the dependant variable.

Experiment 3A Figure 15 illustrates the change in Ice FingerTw temperattire per

storage condition across the six time interval measures and Tables 1-3 list the mean

temperattire measures and average temperattire change of Ice FingersTw stored in each of

the three methodologies. For Ice Fingers^M stored in water warmed to body temperature,

the initial temperattire (-10.505° C) measured at time 0 was similar to that of Ice

Fingers™ stored at ambient (-9.165° C) and ice temperattire (-11.820° C). However, after

the initial 10-minute interval there was a considerable change in the Ice Finger M

temperature with an average increase in temperature of about 41°. Also note that even at

the warmest measured temperature (about 31° C), the intemal temperature of the Ice

Finger^M in this condition never reached that of body temperature. Over the next four

temperature measurement readings, the intemal Ice Finger^'^ temperature cooled to an

average temperature of about 27° C. From the time interval 2 (measured at 10 minutes) to

time interval 6 (measure at 50 minutes), the Ice Finger^"^ cooled with an average

temperature drop of about 1° per 10-minute interval.

52

10 20 30

Time (Minutes)

40 50

Body Temperature Ambient Temperature Ice Temperature

Figure 15. The change in temperature of Ice Fingers™ stored at body temperature (warm water), room temperature, and in a cup of ice over 6, 10-minute time intervals.

Time Interval

1

2

3

4

5

6

Body Temperature

Mean

-10.505

30.620

29.940

28.690

27.560

26.590

SD

1.387

1.575

1.250

1.067

0.928

0.849

Ambient Temperature

Mean

-9.165

-6.005

-4.570

-3.560

-2.085

1.279

SD

1.138

0.638

0.459

0.811

1.728

2.660

Ice Temperature

Mean

-11.820

-8.340

-6.335

-4.920

-3.980

-3.050

SD

1.323

1.040

0.870

0.750

0.743

0.862

Tab e 9. The mean temperature and standard deviation (SD) per time interval for Ice Fingers^M stored at body, ambient, and ice temperature. The 6 time measurement intervals were every 10-minutes from time 0 to 50 minutes.

53

Change in Time

Interval

Time 1 to Time 2

Time 2 to Time 3

Time 3 to Time 4

Time 4 to Time 5

Time 5 to Time 6

Body Temperature

Average Temp. Change

-10.505 to 30.620

30.620 to 29.940

29.940 to 28.690

28.690 to 27.560

27.560 to 26.590

Average Change in Degrees

41.125°

-0.68°°

-1.25°

-1.13°

-0.97°

Ambient Temperature

Average Temp. Change

-9.165 to -6.005

-6.005 to -4.570

-4.570 to -3.560

-3.560 to -2.085

-2.085 to 1.279

Average Change in Degrees

3.16°

1.435°

1.01°

1.475°

3.3645°

Ice Temperature

Average Temp. Change

-11.820 to -8.340

-8.340 to -6.33

-6.33 to ^ .920

-4.920 to -3.980

-3.980 to -3.050

Average Change in Degrees

3.48°

2.005°

1.415°

0.94°

0.93°

Table 10. The average temperature change and the average change in degrees per change in time interval for Ice Fingers^ ' stored at body, ambient, and ice temperature.

Experiment 3B - Again, a graphical depiction of experiment results can be found

in Figure 15 and a list of descriptive statistics can be found in Tables 9 and 10. As stated,

the initial temperattire of the Ice FingersTw stored in ambient temperattire were similar to

those of Ice Fingers™ stored in water warmed to body temperattire and those stored in a

cup of ice. However, unlike Ice FingersTM stored in body temperattire water, the Ice

FingersTM stored in ambient temperattire warmed much more slowly. The Ice FingersTM

in this condition only warmed about 1-3° C per 10-minme time imerval, with the fastest

warming taking place in the first and final 10-minute intervals. Of note in this

experiment. Ice FingersTM did not warm above freezing (i.e., 0° C) until the final

temperattire interval measured at 50 minutes. However, even at 50 minutes, the average

Ice FingerTM temperattire was only 1.279° C. All other intemal Ice FingerTw temperattire

measures for this condition remained below freezing.

54

Experiment 3C - Results for Experimem 3C are also displayed in Figure 15 and

listed in Tables 9 and 10. For Ice Fingers™ stored in a cup of ice, the initial temperattire

was similar to those stored in ambient and body temperature water; however. Ice

Fingers™ in this condition warmed slower than in the other two conditions. For Ice

Fingers™ stored in a cup of ice, the average temperattire gain per 10-minute interval was

only 1-2°. Also in this condition. Ice Fingers™ did not warm to 0° C, even after 50

minutes.

Statistical Analysis Experiment 3 - The results of Experiment 3 were statistically

analyzed via a 3 x 6 (i.e.. Storage Method x Time Measurement Interval) repeated

measures ANOVA, with the change in Ice Finger M temperature as the dependent

variable. As noted in the experimental descriptions, there was a difference in the

temperature chracterisitcs of the Ice FingersTM based on storage methodology. These

differences were reflected in highly significant main effect of Storage Method [F(2, 57) =

5031.812,;? < 0.0001].

It was also noted that there was a difference in Ice Finger^'^ temperature across

each of the six time interval measures. These differences in Ice FingerT"^ temperature

across time measurement intervals were also revealed to be a significant main effect for

Time Measurement Interval in the warm water condition [F(5, 285) = 5178.631,/? <

0.0001]. On the other hand, there was no main effect of Time Measurement Interval in

the ambient condition.

To further analyze the temperature characteristics of the Ice Finger'' ' based on the

two best storage methodologies (i.e., ambient and ice), a post hoc measure was performed

to specifically determine significant differences between these two storage methods. Post

55

hoc testing revealed a significant difference between the storage methodologies of

ambiem and cup of ice (Fisher's PLSD;p < 0.05 and Bonferroni/Dumi;/? < 0.05).

Experiment 4

Fifteen Ice FingersTM were submitted to the Texas Tech Health Sciences Cemer

Department of Clinical Lab Sciences for culttiring over three conditions. Table 11 lists

culttire results for each Ice FingerTM in each condition at 24 and 48-hour intervals. As

expected, the positive control. Staphylococcus epidermidis, demonstrated moderate and

heavy growth on BAP at both 24 hours and 48 hours respectively, and the negative

control did not demonstrate any growth at wither 24 or 48 hours. Similar to the negative

confrol, no growth was present on cultures from any of the 15 Ice FingersTM at either 24

or 48 hours.

Specimen Positive control Negative control MC#1 MC#2 MC#3 MC#4 MC#5 MD#1 MD#2 MD#3 MD#4 MD#5 0P#1 0P#2 OP#3 0P#4 0P#5

24 hour growth Moderate growth NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG

48 growth Heavy growth NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG NG

Table 11. The results of culttiring Ice Fingers™ over three conditions: MC) MadaCide-FD, MD) Mild detergent, and OP) out of package. NG represents no growth.

56

CHAPTER IV

Discussion

Introduction

For this bench sttidy four major experiments examining the safety and

temperattire characteristics of the AliMed® Ice FingerTM were conducted. The results

indicated that the Ice FingerTM was a safe device that may potentially be used in the

management of patients with dysphagia. The results also indicated that the Ice FingerTM

retained cold temperatiires sufficient for stimulating cold receptors during thermal

stimulation. The clinical implications of these experiments seem to outweigh any study

limitations, but future clinical studies are recommended.

Safety Characteristics

Overall, the results of this study indicated that the AliMed® Ice FingerTM is safe

for single and repeated patient use. The Ice FingerTM appeared to be durable across

varying temperature properties and site of weight application. Safety was also

demonstrated based on the lab results of cultured Ice FingersTM across all cleaning

methodologies.

The first research question of Ice FingerTM durability was answered as weight was

applied at two specific points and distributed across the casing surface for three

conditions of varying temperatures: ambient, regular frozen, and solid frozen. Out of 60

total Ice FingersTM examined in this experiment, only 1 Ice FingerTM in the solid frozen

group mptured after the application of 4200 g. As such, the results of this experiment

57

indicated that in general neither a room temperattire nor a frozen Ice FingerTM will

mpttire when considerable force is applied at specific points, such as a bite, or disttibuted

across the casing, as in tongue compression during sucking. This information is

especially important for swallowing therapists who encounter patients with a tonic bite

reflex. As discussed eariier, a tonic bite reflex may be elicited through stimulation of the

teeth or gums, which could possibly occur during thermal stimulation using an Ice

FingerTM. The elicitation of the bite reflex would cause the patient to bite down on the Ice

FingerTM ^t a specific point. Patients who become fmstrated with thermal stimulation

tasks may also voluntarily bite down on the thermal stimulation device before removal

from the oral cavity. The results of research question one should serve to reassure

clinicians that the Ice FingerTM js safe and will not mpture even with significant sucking

pressure or bite force.

Not only have these results indicated that the Ice FingerTM is durable at various

points and distributed weight, the results of this study also indicated that the freezing

temperatiire did not affect the durability of the Ice FingerTM casing. Although it is not

recommended for use in an unfrozen state, the Ice FingerTM ^an be frozen at different

temperatures without compromising its stmctural integrity.

The second research question of Ice FingerTM durability over time was answered

following repeated freezing, thawing, and cleaning with either a mild detergent or with a

germicidal solution. Out of the 80 total experimental Ice FingersTM used, only 2 mpttired.

The results of this experiment indicated that the Ice FingerTM js safe for both the first use

as well as for repeated use, even with multiple cleaning using either a mild detergent or a

germicidal solution. Further, the germicidal solution did not compromise the durability of

58

the Ice FingerTM and, therefore, may be considered an alternative to cleaning the Ice

FingerTM with mild soap in fiittire sttidies. The Ice FingersTM demonstrated durability

over time, which should encourage swallowing therapists to use an Ice FingerTM multiple

times with the same patient without fear of casing mpttire.

The fourth research question regarding the sterilization properties of the Ice

FingerTM was answered through culturing of the Ice FingersTM following removal from

shipping package, following cleaning with a mild detergent, and following cleaning with

a germicidal solution. As indicated previously, the manufacturer recommended that Ice

FingersTM be cleaned with a mild detergent before the first use and after each thermal

stimulation therapy session. Of the 15 total Ice FingersTM culttired in this experiment,

none developed any growth even after 48 hours. The results of this experiment indicated

that the Ice FingerTM, across properties of non-cleaning and cleaning with either mild

detergent or a germicidal solution, is safe for patient use and most likely will not lead to

contamination during the first treatment session. However, the results of this experiment

may not be generalized to repeated patient use at this time. The sterilization properties of

the Ice FingerTM following multiple uses with patients and cleaning with a mild detergent

should be explored in fiiture studies.

Patient safety was indirectly examined in Experiment 3, which also deserves

mentioning here. Experiment three not only considered the best storage methodology for

the Ice FingerTM, but it also considered the effects of a frozen Ice FingerTM placed in

water warmed to body temperature. This experiment attempted to replicate the condition

of a frozen Ice FingerTM making contact with oral mucosa, which may speak to the

possibility of mucosal damage sustained during thermal stimulation with an Ice FingerTM.

59

To this end, the water wanned to body temperattire never dropped below 26° C over a

50-minute time period. This indicated that a frozen Ice FingerTM would not cause harm to

oral mucosa as the water remained above freezing.

In summary, results of this research sttidy indicated that the Ice FingerTM appears

to be safe and durable for single and repeated use. When selecting a thermal stimulation

device, a speech-language pathologist need not fear the Ice FingerTM will mpttire or harm

the patient.

Safety Limitations

Although this study indicated that the Ice FingerTM is safe for patient use,

limitations to this study may exist. For example, individuals demonstrating a tonic bite

reflex can be expected to present with a bite force correlated with the maximum amount

of weight used in these experiments (i.e., 4200 g). However, the literature reveals that a

wide range of voluntary bite forces is possible. Although it is doubtful that an Ice

FingerTM would mpture with an increased bite force due to the limited number of Ice

FingersTM that mptured during this safety study, it is currently unknown whether or not

the Ice FingerTM casing would mpture or tear under a condition of increased bite force.

Furthermore, it was postulated that a bite with force up to 4200 g would not

mpture the Ice FingerTM; however, the searing or tearing action of the teeth could not be

replicated during this study. Even though puncture due to dentition could not be imitated,

the nylon seine twine was similar to maxillary dentition in that it was narrow, resembling

a row of upper teeth. Also, due to the nattire of this bench study, both a superior and

inferior constriction, like that achieved via maxillary and mandibular dentition during a

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bite, could not be replicated due to the limited feasibility of creating such a condition in

the laboratory setting. The replication of this condition should be attempted during a

fiittire clinical sttidy to determine if superior and inferior constriction significantly affects

the frequency of Ice FingerTM rupttire.

The safety characteristics of the AliMed® Ice FingerTM were examined for not

only possible mpttire following single use, but possible mpttire following multiple uses.

The manufacttirer recommended that the Ice FingerTM be used multiple times with the

same patient. Another potential safety limitation may relate to repeated use replication

(i.e.. Experiments 2C and 2D), in which a 200 g weight was suspended from each Ice

FingerTM for approximately 1 hour. Although no previous literattire exits on this point,

during repeated use in human subjects, the force applied to the Ice FingerTM casing may

in fact be greater than 200 g. Therefore the amount of weight used to replicate repeated

use may not be equivocal to the force imposed during daily use. However, the simulated

use trials of this study were conducted in such a way as to replicate a thermal stimulation

therapy session lasting one hour, which is considered greater than the maximum time a

swallowing therapist would typically see a patient for thermal stimulation.

Similar to the recommendation of multiple uses, the manufacturer also

recommended that the Ice FingerTM be cleaned with a mild detergent and stored in a

sterile container following patient use, although the manufacturer did not specify an exact

cleaning or storage methodology. For this bench study. Ivory® liquid hand soap and

MadaCide-FD Germicidal Solution were used as cleaning agents. At the time of this

study, the clinical applicability and/or patient safety of using MadaCide-FD as a cleaning

agent for the Ice FingerTM was undetermined. However, according to the directions for

61

use, located on the bottle, MadaCide-FD could be used on "plastic and other hard, non

porous surfaces of respirators and respirator facepieces and CPR fraining mannequins."

Furthermore, MadaCide-FD has been recommended and used for cleaning

videosfroboscopy equipment, which is thought to be safe for intra-oral patient use.

Although exploring the safety characteristics of the Ice FingerTM stored in

different containers was beyond the focus of this study, a sterile container was utilized in

Experiment 4. During Experiment 4, Ice FingersTM were stored in 50 ml centriflige tubes

and placed in a Styrofoam rack. This type of storage methodology was considered more

appropriate than plastic sandwich baggies due to sterilization concems and may be a

clinically applicable storage methodology.

Temperature Characteristics

The temperature characteristics of the Ice FingerTM ^^Q^Q also examined in this

research study. The "Directions for Application, Use and Care" sheet provided with each

package of AliMed® Ice FingersTM stated that the Ice FingerTM had the ability to hold

cold temperatiires for an extended period of time (AliMed® inc., 2001). The results of this

sttidy indicated that the Ice FingerTM did indeed hold cold temperattires sufficient for

thermal stimulation over all three conditions of varying storage temperattires for 50

minutes. Even during the warmest condition, storage in a cup of water warmed to body

temperattire (37° C), the frozen Ice FingerTM retained cold temperattires sufficient for

stimulating cold receptors during thermal stimulation.

As previously stated, cold thermal stimulation has been found to be most effective

when the mucosal temperature was decreased to between 20°C and 34.5°C, the range in

62

which cold receptors are most sensitive (Kaatzke-McDonald, Post, & Davis, 1996).

During Experimem 3, the oral cavity and mucosal temperattire was represented by water

temperattire. The water warmed to body temperattire, which represented the temperattire

in the oral cavity and associated mucosa, stayed in the range of 26°C to 29°C. This

indicated that the Ice FingerTM sufficiently reduced the warm water temperattire to a

range in which cold receptors in the oral cavity would be sensitive during thermal

stimulation.

When storing at ambient room temperattire, approximately 22° C, a frozen Ice

FingerTM only loses about 10° (i.e., from an average of-9° C to an average of 1° C over

50 minutes). The Ice FingerTM stored at room temperature stayed below 0° C for 40

minutes, and, on average, only warmed to about 1° C after 50 minutes. These results

indicated that it may not be necessary to store the Ice FingerTM in ice as typically

recommended for use with a laryngeal mirror. Another clinical implication of these

results could be that a speech-language pathologist may be able to transport two different

frozen Ice FingersTM at room temperature for back-to-back thermal stimulation sessions.

While the swallowing therapist performs thermal stimulation during the first session, the

second frozen Ice FingerTM can be stored at room temperature for the second session,

without concems of losing cold temperature sufficient for thermal stimulation.

The results of this study ultimately indicated that a frozen Ice FingerTM stored in a

cup of ice is the best strategy for keeping the Ice FingerTM colder, longer (i.e., on average

only lost approximately 8° C over 50 minutes). The Ice FingerTM stored in a cup of ice

stayed below 0° C for 50 minutes. Therefore, the Ice FingerTM should be stored in a cup

of ice between thermal stimulation trials. Using this storage strategy, the Ice FingerTM

63

would be expected to stay below 0° C for an entire session of multiple thermal

stimulation frials. Based on the results of these experiments, it can be postulated that the

manufacturer's claims of extended cold retention were correct.

Miscellaneous Observations

The AliMed® Ice FingerTM casing is made of clear plastic, which is filled with an

unknown malleable substance. The Directions for Application, Use and Care indicate that

the Ice FingerTM "measures 4 inches long (below the handle)" (AliMed inc., 2001).

During the course of this sttidy, it was observed that the length of the Ice FingersTM

ranged from 6.5 cm to 9.5 cm. The variability in size of the Ice FingersTM is depicted in

Figure 16.

Figure 16. Ice FingersTM used in this sttidy varied in size.

The appearance of the Ice FingerTM casing also varied, in that the gelatinous

material filling the casing either appeared "clear and smooth," or "bubbly," as shown in

Figure 17. The terminal ends of the Ice FingersTM also varied, given that some of the

64

temiinal ends protmded causing a sharp end when frozen. These profruding ends may

potentially scrape the oral mucosa and cause damage if the swallowing therapist is not

carefiil when inserting the Ice Finger™ into the oral cavity. This type of protmding end i

compared to an Ice Finger™ with a flat end in Figure 18. This potential for damage

should be explored in fiittire patient sttidies.

Figure 17. Ice FingerTM A depicts the "bubbly" appearance as compared to Ice Finger™ B, which is clear in appearance.

Figure 18. Ice FingerTM A depicts a protmding end as compared to Ice FingerTM g which has a flat end.

Conclusion

Overall, the results of this study indicated that the AliMed® Ice FingerTM is

durable and safe for single and repeated patient use across various conditions of freezing

65

and cleaning. The manufacturer's claim of cold temperature retention sufficient for

thermal stimulation was also proven to be correct. The Ice FingerTM jg a device that

allows the swallowing therapist more freedom during thermal stimulation tasks, in that

the Ice FingerTM can be used with a variety of patients and is easier to maneuver and hold

than historical thermal stimulation devices. The Ice FingerTM is also easier to clean, in

that only soap and water may be necessary. Based on bench study results, the Ice

FingerTM [^ recommended for patient use during thermal stimulation.

66

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