PHD Resident Airway Lecture Alan I. Frankfurt, MD

PHD Resident Airway Lecture

Alan I. Frankfurt, MD

Alan Frankfurt, M.D.;Gary Weinstein, M.D.

Why Train?

“…my life flashed before my eyes.” Meaning?

Initial response to any stressful/life threatening experience…

Mental rolodex scanning “Have I ever been in or seen a situation like this before?”

What worked then?” What did not work?

Why train? Populating your mental rolodex Making the unfamiliar, familiar in a controlled environment.

Training: USAF Experience

USAF Red Flag Training Exercise90% of all fighter pilots who died in combat, did

so in their first 10 missions. Learning curve: First ten missions. Flying those first ten missions in a training

environment. Red Flag Training Exercise.

Airway Class Objective

Use this airway training as your own Red Flag ExerciseTraining

Lecture Hands on lab Visualization

Airway Topics

Relevant airway anatomy Innervation of the airway Anesthesia of the airway PU<92% Concept Airway examination

6 D’s

Airway Definitions and Concepts Jim Rich, CRNA

Critical airway event: ability to rescue the airway. CICMV Intubation difficulty

Definition: difficult airway SPO2<92%

100% Oxygen PPV

Crash airway: early recognition for patient salvage. PU<92 IRS

Intubation Rescue breathing Surgical airway

Airway Evaluation: 6 D’s Difficulty airway options Intubation rescue options

Law of insanity AB4C’S

Overview of Upper Airway Anatomy:Structure and Function

Nares: Nasal Turbinates Turbinate bones

Superior Inferior Middle

Function 10,000 L of ambient air pass

through the nasal airway per day and

1 L of moisture is added to the air during this process.

Inferior turbinate Highly vascular membrane

Vasoconstriction prior to instrumentation

Nasotracheal tube Nasopharyngeal airway

Pharynx

Location The pharynx situated

between the nose and larynx.

3 Divisions Nasopharynx Oropharynx Hypopharynx

(Laryngopharynx)

The Pharyngeal Anatomic Divisions

Nasopharynx Termination of the

turbinates and nasal septum

Soft palate. Oropharynx

Soft palate Hyoid bone.

Hypopharynx Hyoid bone First tracheal ring

AKA Laryngopharynx

Larynx

Base of the tongue (hyoid bone) -> first ring of the trachea.

Opposite C3-C6 Function

Watchdog of the airway Swallowing

Organ of phonation Bones

Hyoid Cartilages

Epiglottis Thyroid Cricoid

Laryngeal Anatomy

Cricoid Cartilage

Anatomic lower limit of the larynx.

Only complete cartilaginous ring in the upper airway.

Attaches to the thyroid cartilage by the cricothyroid membrane. Laryngotracheal anesthesia Surgical airway

Identification in the patient with poor anatomic landmarks.

Cricothyroid artery

The superior thyroid artery First anterior branch of the

external carotid artery. The cricothyroid artery

Branch of the superior thyroid artery

Runs in the upper portion of the cricothyroid membrane.

Surgical airway Tracheal hook placement

Airway Innervation: 5-9-10

Innervation of the Nasal Passage and Nasopharynx: CN 5

Anterior 1/3 of the nares. Anterior ethmoidal

nerve

Posterior 2/3 of the nares. Greater and Lesser

Palatine nerve

Anesthesia for the Mouth and Oropharynx: CN 9

AnatomyGlossopharyngeal

nerve (CN9)

Anesthesia for the Mouth and Oropharynx: CN 9 Poster 1/3 tongue,

Gag reflex Vallecula, Anterior surface of the

epiglottis (lingual branch), Posterior and lateral walls

of the pharynx (pharyngeal branch), and

Tonsillar pillars (tonsillar branch).

Laryngeal Innervation: CN 10

CN X (Vagus) Superior laryngeal nerve

Internal laryngeal nerve.

Posterior epiglottis to vocal cords.

Penetrates at the thyrohyoid membrane.

External laryngeal nerve.

Cricothyroid muscle

Innervation of Trachea and Vocal Cords

Recurrent Laryngeal Nerve Sensory innervation of

the tracheobroncheal tree up to and including the vocal cords.

Intrinsic laryngeal musculature except cricothyroid muscle.

Airway Anesthesia

Airway manipulations issue without adequate anesthesia. Patient comfort Hemodynamic response Valsalva

Airway anesthesia options “Spray and Pray”: Topicalization of the airway with local

anesthesia Entire airway may be anesthetized using topical anesthesia

Nerve block ? Glossophyngeal nerve Superior laryngeal nerve “Transtracheal nerve block”

Airway Local Anesthesia Drug Absorption

Topical anesthetic absorption Alveoli>Tracheobroncheal tree>Pharynx

Airway Anesthesia Medications Cocaine

4% and 10% solutions 3 mg/kg (200 mg maximum dose) 5cc’s in a 70kg person.

Benzocaine Rapid onset and short duration (10 minutes) Cetacaine

Bezocaine, Tetracaine Methemoglobinemia

Cyanosis, fatigue, weakness, headaches, dizziness and tachycardia Massimo pulse oximeter

Lidocaine 1%, 2% and 4% solutions

4% lidocaine/Afrin mixture Rare to see toxic reactions within the context of airway anesthesia.

Lidocaine 5% ointment Lidocaine 2% jelly

Loaded in a syringe Viscous lidocaine.

Swish and swallow Tetracaine

Toxicity 100mg (40mg)

Goal of Airway Anesthesia

Airway Preparation for Awake Airway Manipulation

First: Never sacrifice patient safety for patient comfort. What are the systemic effects of inadequate airway anesthesia?

Coughing, straining, valsalva Hypertension and Tachycardia

Myocardial oxygen consumption Increased ICP Increased IOP

How to prepare for success prior to anesthetizing the airway. Maintain the ability to communicate with the patient. Dry the airway.

Maximize effectiveness of the LA applied to the airway. Dilution of LA concentration by oral secretions

Decreases LA effectiveness Comfortable patient is a cooperative patient:

Sedation/analgesia/anesthesia Intravenous medications Transmembrane medication administration

Patient Preparation for Anesthesiaof the Airway

Antisialogogues (Drying Agents) Robinal 0.2-0.4 mg IV Atropine 0.5-1.0 mg IV

Vasoconstrictor Afrin spray Phenylephrine 1% spray

Anxiolytics and Analgesia Versed

Flumazenil Fentanyl

Naloxone Monitors

Pulse Oximetry Supplemental oxygen

Key Airway Anesthesia Principles: Timing, Positioning and Lubrication

Timing Give your preparation drugs time to work.

Anticholinergic Vasoconstriction agents

Positioning Position yourself to succeed.

Go slow Monitor the patient

Masimo pulse oximetry Don’t burn any airway bridges

Reversible agents Lubrication

The entire airway can be anesthetized topically with generous amounts of anesthetic jelly and ointment.

Recurrent Laryngeal Nerve Block:AKA Transtracheal Block Indications

Anesthesia for the laryngotracheal mucosa.

Awake intubation, Retrograde intubation, Cricothyrotomy (surgical or

percutaneous), Abolishment of gag reflex

or hemodynamic response associated with intubation.

Medications 4% Lidocaine 1-2% Lidocaine

Recurrent Laryngeal Nerve Block:AKA Transtracheal Block Patient positioning

Supine in the “sniffing” position Technique

Cricothyroid membrane identification. Local anesthesia skin wheal: Conscious verse

Unconscious Patient 2-3cc of 4% Lidocaine drawn into a 5cc syringe

20G Angiocath needle. Identification of the airway

Loss of resistance Air bubbles signals entry into the larynx.

How I Do It: Robinal Afrin/Afrin and 4% Lidocaine cocktail.

Nasal manipulation. Sedation +/- Nebulized 4% Lidocaine 2-3cc

Prior to the application of gels or ointments.

4% Lidocaine in a syringe dribbled down the nares.

(Viscous Lidocaine swish and swallow).

Oral airway/Nasal trumpet with 5% Lidocaine gel. CN9 gag reflex: posterior tongue.

Transtracheal block with 4% Lidocaine with 22G-25G needle or 20 G Angiocath. Above and below vocal cord

anesthesia.

PU-92 Concept

Crash Airway

Crash Airway Concept: Walls, R.

Teaching Goal: To identify patients in extremis. Patients who are going to die unless you intervene

quickly and decisively. Who are these patients?

Altered mental status with airway compromise. Lethal combination: M/M increased 50-75% Unconscious

Apneic or having agonal respirations. Arrested or near death. Anticipated to be unresponsive and tolerant to laryngoscopy.

Getting Your Arms Around The Crash Airway: PU-92

Crash airway Meant to convey an unmistakable sense of urgency. Circling the drain!

From conceptual idea to clinical action. PU-92 concept

PU-92: Reflects the lethal combination of a cerebral insult (ischemic or

traumatic) and hypoxia. Critical nature of early airway support in the face of brain

injury. Airway compromise in a patient with compromised

cerebral circulation may DOUBLE mortality. Provides a quick and reliable tool to recognize these patients

early and intervene.

PU-92 Parameters

Level of consciousness SpO2 level

PU-92 Parameters: LOC and SpO2

Level of consciousness using the AVPU system Alert, Voice response, Pain response only or Unresponsive McKay et al:

P or U response corresponds to a GCS<9 GCS<9 immediate indication for intubation

Patients SpO2 level SpO2<92%, despite:

Maximum airway efforts utilizing: PPV manual airway opening techniques 100% oxygen ( if available).

If SpO2 unavailable, use a RR <10 or > 30/breathes per minute. Use of SpO2 in the field environment.

Masimo Movement algorithm Low perfusion algorithm Co and MetHg

PU<92: Now What? The Crash Airway Response

Patients require immediate improvement in Ventilation and Oxygenation Treatment options: IRS

Intubation Rescue Ventilation Surgical airway

Treatment options are decided upon after an Airway Evaluation Airway Evaluation reveals:

No difficulty anticipated One attempt at direct laryngoscopy and Intubation (I). Failed intubation fall back to Rescue Ventilation (R)

Class 2a agent Surgical airway (S)

Difficulty anticipated Rescue Ventilation Surgical airway

Rescue Ventilation

Positive Pressure Ventilation with Class 2a adjunctive airway device. Class 2a: therapeutic option for which the weight of evidence is in favor

of its usefulness and efficacy. ETC: Esophageal-tracheal Combitube LMA (King LT)

Class 2a devices are supraglottic devices which do not address obstruction of the airway at the glottic or subglottic level.

Endotracheal tube Cricothyrotomy

Airway literature reveals that rescue ventilation is often effective in providing ventilation and oxygenation in the following conditions CMVCI Failed intubation

ECT: Esophageal Combitube Tube



LMA

King LT

Summary: Crash Airway Confirm a crash airway exist:

Patient in extremis. PU-92.

Call for help. Maximize airway support

Manual maneuvers Airway devices: OA and NT

PPV with 100% O2 as available Identify possible difficulty airway Pay the “IRS”

Intubation attempt Only if airway appears easy to intubate Airway evaluation

6 D’s Rescue ventilation

If intubation fails or airway appears difficult SpO2>92

Yes-monitor airway and reassess need for definitive airway No->

Surgical airway

Airway Evaluation

6-D Method of Airway Assessment


6-D method of airway assessment is meant to assist health care providers in remembering the six signs that can be associated with a difficult intubation.

Each sign begins with a D. The potential for airway difficulty is

generally proportional to the number of signs observed.


1. Disproportion. 2. Distortion. 3. Decreased thyromental distance (3). 4. Decreased interincisor gap (2). 5. Decreased range of motion in any or all

joints of the airway (1). 6. Dental overbite.


Disproportion Size of tongue in relation to the oropharyngeal size.

Obstructed laryngoscopic view of airway. Airway trauma (blunt or penetrating) with resultant swelling. Patient’s anatomy Assessment

Mallampati Classification Predicting airway disproportion problems:

Mallampati class 4 (3?) Swelling or protruding tongue

Blunt or penetrating injury Receding mandible

Mallampati Airway Classification System

Class 1: soft palate, uvula, anterior and posterior pillars are visible.

Class 2: soft palate and uvula are visible

Class 3: only soft palate and base of uvula visible.

Class 4: hard palate visible, but not the soft palate.


Distortion Etiology:

Neck mass, neck hematoma, neck abscess, previous surgery or trauma.

Predicting airway distortion problems: Voice change Subcutaneous emphysema Laryngeal immobility Non palpable thyroid and/or cricoid cartilage. Neck asymmetry

Tracheal deviation Subcutaneous emphysema


Decreased thyromental distance Reflects an anterior larynx and decreased sub-mandibular

space. Problem:

Unable to displace the tongue into the submandibular space, out of the view of the laryngoscopist.

Predicting airway difficult resulting from decreased thyromental distance: Thyromental distance <7 cm (<3 FB)

Measured from the superior aspect of thyroid cartilage to the tip of the chin.

Underdeveloped mandible


Decreased interincisor gap Reduced mouth opening

Reduced ability of the oral cavity to accommodate airway instrumentation.

Predicting airway difficulty secondary to decreased incisor gap distance: Distance between the upper and lower incisors is <4 cm ( 2 FB )

Mandibular condyle fracture. Rigid cervical collar. TMJ dysfunction


Decreased range of motion in any or all of the joints of the airway. Atlanto-occipital joint, cervical spine and TMJ.

Sniffing position. Predicting airway difficulty secondary to decreased ROM of

joints involved in assuming the sniffing position: Head extension < 35 degrees Neck flexion < 35 degrees Short, thick neck Cervical spine collar or C spine immobilization


Dental overbiteLarge angled teeth disrupt the alignment of

the airway axes and possibly result in decreased interincisor opening.

Predicting airway difficulty secondary to dental overbite:Protruding maxillary incisors.

Treatment of Airway Loss: Operator Skill and Equipment Requirements.

Causes of Airway Obstruction: LIFT

L-Level of consciousness Trauma or Medications. Loss of muscle tone

Jaw lift Nasal trumpet

I-Inflammation Burns

Early intervention Advanced airway techniques

Anaphylaxis F-Foreign body

Blood clots, teeth, bone, food… Finger sweep, positioning

T-Trauma

If it was pushed in…pull it out.

Treatment of Airway Obstruction: AIR

A-Assess for airway obstruction Recognition Signs and symptoms

Dysphonia, noisy breathing, RR<8 or >30, use of accessory muscles.

I-Improve the airway Positioning

Position of comfort Recovery position Cervical spine precautions.

Mechanical Jaw thrust, Chin lift

Nasal trumpet(s) R-Remove any debris

Finger sweep

Indications for Tracheal Intubation

Airway protection and risk for aspiration. Need for a definitive airway. Patient will be going to OR and has an unstable airway. Respiratory failure/arrest and in need of mechanical ventilation PEEP administration GCS<9 or on AVPU scale a “P” or “U” ACLS drug administration Pulmonary toilet Hypoxemia refractory to oxygen therapy Uncontrolled seizure activity Depressed LOC in a trauma patient Combative patient with a compromised airway.

Emergency Indications for Intubation

Can’t protect airway Gag reflex absent in 37% population Ability to swallow and manage secretions

Can’t maintain Ventilation/Oxygenation Inability to maintain SpO2>92% on oxygen, PaCO2>55 or 10 torr above baseline. RR <8 or >30/ minute

Expected decline in clinical status. Deterioration/Impending compromise Transport

Contraindication to RSI

Evaluation of the patient’s airway reveals that laryngoscopy and intubation would not be successful 6 D’s

Unfamiliarity with the technique Do what you do all the time.

Lack of any rescue ventilation options Plan A, B, C.

Other safer options Awake intubation under topical and nerve block anesthesia Cricothyrotomy under local anesthesia

Local infiltration Transtracheal block

Don’t burn an airway bridge. A lousy airway is better than no airway.

Direct Laryngoscopy Checklist Variety of laryngoscopy blades Variety of Endotracheal tube (ETT) sizes Stylett the ETT Boogie Test balloon on ETT Class 2a rescue ventilation device Adequate muscle relaxation if indicated Head position Suction Test IV patency Pre-treatment

Oxygen Vagolytic Non particulate antacid

RSI indicated? Assistant present as available Look for the epiglottis first Don’t shotgun the laryngoscope Control the tongue Don’t lever the blade. Intubation confirmation device

Techniques to Rescue a Difficult Intubation

Avoid the Law of Insanity

Law of Insanity

Doing the same thing over and over again while expecting a different result.

Techniques to Rescue a Difficult Intubation

Access Visualization Passage of the ETT

Techniques to Rescue a Difficult Intubation: Law of Insanity AB4C’S

AxisBoogieBURPBlade: size and typeBlockCricoid pressure: let upStylet/Smaller ETT

Techniques to Rescue a Difficult Intubation Sniffing Position

Head extension Neck flexion

Onto the shoulders

20-30 degree angle

Aligning Axes of Upper Airway

Extend-the-head-on-neck (“look up”): aligns axis A relative to B

Flex-the-neck-on-shoulders (“look down”): aligns axis B relative to C

C

ABA

B

C

TracheaPharynx

Mouth

External Laryngeal manipulation (ELM): BURP BURP

Laryngoscopist hand placed on top of assistant’s hand.

Backward, Upward, Rearward Pressure.

Thyroid cartilage

Gum Elastic Bougie

Gum Elastic Bougie Most beneficial with a Grade III larygoscopic view. Works synergistic with other airway maneuvers

ELM: BURP airway manipulation Jaw thrust/chin lift.

Indicators of successful tracheal placement of the bougie Tracheal clicking Hold up

Leave the laryngoscope in place during ETT insertion with the bougie in place. Rotate the ETT counter clockwise 90 degree to prevent the tip of the ETT

from hanging up on laryngeal structures during passage.

BURP Maneuver

Difficult intubation rescue option Improve visualization of the larynx by at least one grade.

Knill RL; Can J Anesth 1993;40:279-82 BURP maneuver results in displacement of the larynx in three

specific directions to place the vocal cords in view of the operator: Backward-Thyroid cartilage displacement dorsally (backward)

as to abut the larynx against the bodies of the cervical vertebrae. Upward-Thyroid cartilage is moved cephlad about 2 cm until mild

resistance is met. Rightward-laterally to the right approximately 0.5-2.0 cm. Pressure

Employing the BURP maneuver, the assistant moves the larynx until mild resistance is met.

BURP Maneuver Mechanism of Action

As a result of the BURP maneuvers, the glottis is moved directly into the line of vision. Let’s examine why this is true: The laryngoscope enters the oral cavity from the right and

displaces the tongue toward the left. Tongue attached to larynx. Hence the larynx is moved leftward as well.

Resulting visual pathway is somewhat to the right side of the oral cavity midline.

BURP maneuver may improve visualization of the glottis by moving the larynx more into the line of vision.

Effect of BURP on Visualization

Grade Initial

Inspection

After BURP

Grade 1 0 231

Grade 2 181 38

Grade 3 80 4

Grade 4 12 0

Surgical Airway

Cricothyrotomy

Rapid Access to the Airway or Not.

Indications for Surgical Airway

Clinical Mid face trauma

Blunt vs. PenetratingAirway obstruction above the level of the

cricoid cartilage. Anaphylaxis/Anaphylactoid reactionBurnFailed intubation and failed rescue ventilation

Cricothyrotomy: Rapid 4 Step Technique

Instruments: Rapid 4 Step Technique Scalpel with a no.20

blade, tracheal hook, no. 6 Shiley tracheostomy tube.

Instruments: Std Technique Scalpel with no.11

blade, Trousseau dilator, hemostats, tracheal hook, no. 6 Shiley tracheostomy tube.

Cricothyrotomy: Standard Technique

Steps Identification of the cricoid membrane

Palpation Sternal notch

Dissection 4 cm vertical skin incision over the cricoid membrane. Short horizontal stab wound over the lower portion of the cricoid

membrane. Never remove scalpel blade until tracheal in place.

Stabilization of the larynx with a tracheal hook at the inferior aspect of the thyroid cartilage.

Dilation of the ostomy with a curved hemostat. Placement of the Shiley tube/Endotracheal tube.

Cricothyrotomy: Rapid 4 Step Technique Steps

Identification of the cricothyroid membrane by palpation.

Horizontal stab wound through the skin and cricothyroid membrane with the scalpel.

Non-palpable anatomy: skin incision Stabilization of the larynx with the tracheal hook at the

inferior aspect of the ostomy (on the cricoid cartilage), providing caudal traction.

Placement of the Shiley tube in the trachea.

Cricothyrotomy: Modified Technique

Identification of the cricoid cartilage. Easy Hard

Non palpable and non visualized Sternal notch and work your way upward.

Anesthesia? Local infiltration Transtracheal block

2-4 cm vertical incision overlying the cricoid membrane. Not a cosmetic procedure. Use the entire incision Define your anatomy

No. 20 blade attached to a scalpel for cricoid membrane puncture. Puncture made at the superior aspect of the cricoid cartilage.

Cricothyrotomy: Modified Technique

Tracheal hook applied to the superior surface of the cricoid cartilage. The cricoid cartilage is delivered out of the wound.

Stabilizes the larynx. Prevents blood from pooling in the wound. Not working in a deep hole.

Kelly clamp used to dilate the ostomy. #5-6 ETT/#6 Shiley placed in the ostomy

Bougie Confirmation of tracheal intubation

CO2 detection Capnography Colorimetric SIB (Self inflating bulb)

Questions?

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PHD Resident Airway Lecture Alan I. Frankfurt, MD