Tracheostomy Suctioning and Humidification

SEPTEMBER 30/VOLUME 13/NUMBER 2/1998 NURSING STANDARD 49

AIM AND INTENDED LEARNING OUTCOMESThe aim of this article is to improve the nurse’sknowledge and understanding of adult tra-cheostomy suctioning and humidification. Afterreading this article, you should be able to:�� Describe the reasons for tracheostomy suc-

tioning and humidification. �� Discuss the complications associated with tra-

cheostomy suctioning.�� Demonstrate the recommended suction pres-

sure. �� Discuss the different types, sizes and effects of

suction catheters.�� Illustrate the importance, and types, of humid-

ification.�� Describe a research-based tracheostomy suc-

tion technique.

INTRODUCTIONThe aim of tracheostomy suctioning is to maintaina clear airway and normal breathing sounds andpattern, without exaggerated effort or awarenessof the sensation of breathing, and without caus-ing trauma or hypoxia.

Suctioning is carried out on all adults with atracheostomy, and has been identified as both aroutine procedure (Regan 1988) and one thatmany nurses find worrying due to a lack of rele-vant skills and experience (Grossenbach-Landisand McLane 1979, DeCarle 1985). It can, if notcarried out correctly, cause complications, includ-ing tracheal mucosal damage, hypoxia and evendeath (Regan 1988).

Studies examining the way in which nursescarry out tracheostomy suctioning have suggestedthat two main areas – assessing respiratory insuf-ficiency and following written procedures – werepoor. It was found that techniques used weremore dependent on ward policy, or an individual’schosen technique, than on research (Grossen-bach-Landis and McLane 1979, Harris andHyman 1983, DeCarle 1985).

Tracheostomy suctioning obviously affectsthe person receiving suction. Many people report

a choking sensation, stinging, pressure and theneed to cough while suctioning is carried out. Ithas been suggested that these sensations aredependent on the method used by the practition-er carrying out the procedure (Oermann et al1983).

THE IMPORTANCE OF SUCTION AND HUMIDIFICATIONThe upper airway of a patient with a tracheosto-my has been bypassed. This means that both thewarming and humidification of air, and the normaldefence mechanisms – coughing and mucociliarytransport – are adversely affected.

During quiet respiration, inspired air, the watercontent of which is usually less than 25 per cent,is warmed and humidified through the nose. Bythe time it reaches the nasopharynx, it has beenwarmed to approximately 37oC and is fully satu-rated. The trachea, however, is ill-equipped towarm and humidify inspired air, so the presenceof a tracheostomy causes cold, dry air to reachthe bronchi and lungs (Jackson 1996).

This lack of nasal warming and humidificationwill cause drying of tracheobronchial secretionsand mucosa, which slows mucociliary transport –the sweeping of secretions up the trachea by theaction of tracheal cilia (Van Oostdam et al 1986).The effect of this is that patients with a tra-cheostomy become prone to atelectasis and pul-monary infection, due to:�� The drying of secretions.�� The loss of the normal filtering mechanism of

the nose.�� Reduced mucociliary transport.�� Reduced airway pressure.

Tracheostomy: suctioning and humidificationThis article explains tracheostomy suctioning and humidification. It outlines hownurses can assess the need for tracheostomy suctioning to be performed andpossible complications that may occur as a result of the procedure.

RCN CONTINUING EDUCATION

Article 463. Griggs A (1998) Tracheostomy: suctioning and humidification. Nursing Standard. 13, 2, 49-56.

NOW DO TIME OUT 1

Think of a patient you have cared for with atracheostomy. How did you feel about carrying

out tracheostomy suctioning? What sort ofproblems did you encounter? Think about the

information and skills that are necessary to feelconfident in performing this procedure.

Angela Griggs RGN, is SeniorStaff Nurse, Royal NationalThroat, Nose and Ear Hospital,London.

This article relates to UKCCProfessional Developmentcategories:

Continuing Educationarticles are run inconjunction with the RoyalCollege of NursingInstitute to help you tomaintain and develop yourpractice and can be usedto meet your UKCCrequirements for PREP. All you have to do is readthrough the article, followthe instructions in theTime Out boxes, thenanswer the assessmentquestions that follow. Fillin the answer sheet andreturn it to the Freepostaddress with your fee orfree assessment voucher.

50 NURSING STANDARD SEPTEMBER 30/VOLUME 13/NUMBER 2/1998

The cough is an important and powerfulmechanism used to expel material from the tra-chea. However, it is affected by the presence ofa tracheostomy because the larynx cannot beclosed by the glottis to produce high air flowvelocity on expiration of the cough. People witha tracheostomy use cough-like manoeuvres;although unable to close the larynx, they are stillable to produce compression in the lower tracheaand bronchi. This ability can, however, be com-promised by muscle weakness, pain andreduced mucociliary transport. In these people,alternative means of airway clearance in the formof tracheostomy suctioning is, therefore, required.

COMPLICATIONS OF TRACHEOSTOMY SUCTIONINGTracheostomy suctioning can cause many com-plications if not carried out correctly. The threemain complications are:�� Trauma.�� Hypoxia.�� Infection.Tracheal trauma This is one of the main complicationsof tracheostomy suctioning. Plum and Dunning(1956) identified that tracheal trauma was causedby a combination of high suction pressure, often upto 500mmHg, and the application of suctionpressure on insertion of the catheter, causing thecatheter to adhere to the tracheal wall. Theyrecommended applying suction pressure only whenremoving the catheter, using a Y-connector, and not

‘pinching’ the catheter to obstruct suction pressure.Pinching the catheter to prevent suction pressureon insertion only increased the pressure when thepinch was released.

More recent studies have found that the typeof suction catheter used also has an effect on theamount of trauma caused. These studies suggestthat multi-eyed catheters cause less trauma thansingle-eyed catheters. This is because the smallside holes in the multi-eyed catheter suck in thesecretions, while the single-eyed catheter pulls themucosa as well as secretions into its single sidehole (Sackner et al 1973, Jung and Gottlieb 1976,Fiorentini 1992).

It was found that all suction catheters willcause trauma when pushed against the trachealwall, but the extent of the trauma depends on theindividual practitioner’s technique (Demers andSaklad 1973, Landa et al 1980, Kleibar et al 1988).

Research studies focusing on suction pres-sure have found that no more secretions areremoved at 200mmHg (28Kpa) than at 100mmHg(14Kpa), and that the amount of trauma isincreased at higher pressure. The higher the pres-sure, the more likely it is that the suction catheterwill collapse (Demers and Saklad 1973, Kuzenski1978, Czornik et al 1991).Hypoxia This is a diminished amount of oxygen inthe body’s tissues and occurs during trachealsuction because oxygen, as well as secretions, isremoved. It has been found that the lower theinitial oxygen saturation level, the greater thedecrease in oxygen saturation will be duringsuctioning (Skelley et al 1980). This means thatpatients with decreased lung function, due toairway disease or in the initial post-operativestage, are at risk of developing suction-inducedhypoxia. One solution is to ask the patient tobreathe deeply before and after suctioning; but inpatients who are at risk of hypoxia, oxygensaturation monitoring should be used to assessthe level of hypoxia (Barnes and Kirchhoff 1986).Infection This can occur at the site of trachealtrauma. Bacteria can be introduced duringtracheostomy suctioning if a contaminatedsuction catheter is used. This can lead totracheitis, pneumonia and fistula formation(Brown 1982, Gibson 1983). Suction cathetersshould, therefore, remain sterile until used, onlybe used once and not be used to suction oralsecretions first.

Additional complications are as follows:�� Vagus nerve stimulation – the vagus nerve that

supplies the trachea also supplies the heart;this can be stimulated by the catheter touchingthe tracheal mucosa which can lead to cardiacarrhythmias or to a vaso-vagal attack (Fioren-tini 1992).


Box 1. Assessment of apatient’s breathing sounds

Assessment should includeobservation for:� Abnormal breathing sounds –

‘whistling’, crepitus (‘creps’) ordiminished sounds (Knipper1984)

� Irregular respiration pattern� Changes in secretions – alter-

ations in the amount or consis-tency of tracheal secretionswould indicate either retentionor drying and thickening ofsecretions

� Increase in coughing incidents� Change in the patient’s appear-

ance – an anxious appearancecould indicate respiratory dis-tress. Change in skin colour,and the ability to talk withoutblocking the end of a non-cuffed tracheostomy tube, couldindicate a partly or completelyblocked tracheostomy tube

Fig. 1. A closed system, multiple use suction unit


�� Atelectasis – alveoli collapse, caused by the reab-sorption of air from the alveoli, can be instigatedby high suction pressure and drying of secretions.

�� Paroxysmal coughing – a sudden attack ofcoughing can be caused by irritating the tra-cheal mucosa with a suction catheter.

ASSESSMENT

Tracheostomy suctioning should not be carriedout routinely or at set times, and should only bepractised following assessment of the patient’sbreathing sounds (see Box 1). Suction needs tobe carried out when the patient is unable to clearhis or her own secretions, or is only able to clearthem into the tracheostomy tube with cough-likemechanisms. However, having a tracheostomydoes not necessarily result in the retention ofsecretions or difficulty in clearing the airway. Manypatients are able to cough any secretions out viathe tracheostomy, or into the tracheostomy tubewhich can then be removed and cleared with min-imal use of suctioning.

SUCTION PRESSURE

Suction is the drawing of air out of a space to cre-ate a vacuum that will then suck in surroundingliquids – secretions in tracheostomy suctioning.The suction pressure used can affect the amountof secretions removed, and cause tracheal

mucosa damage and hypoxia. Kuzenski (1978)suggests that tracheal damage is directly relatedto incorrect suction pressure: if suction pressureis too low, the patient’s airway will not be cleared;if it is too high, the suction catheter can adhere tothe tracheal wall, damaging the tracheal mucosa.

High pressure can cause (Serra 1982,Shekelton and Neild 1987): �� Atelectasis (alveoli collapse).�� Mucosal damage.�� Catheter collapse.Suction pressure units vary according to differentscales of measurement used and can be cali-brated by the following indicators:�� The European pressure measurement, the kilo-

Pascal (kPa).�� Millimetres of mercury (mmHg).�� Low, medium and high.

Before suctioning, the scale of measurementand the setting must be checked. In general, thelowest amount of suction pressure needed toremove secretions should be used. A great dealof research into the correct levels of suction pres-sure has been carried out, and the recommendedpressure for adults has been suggested to be(Demers and Saklad 1973, Kuzenski 1978,Regan 1988, Martin 1989):�� 14 to 16kPa.�� 100 to 120mmHg.�� Low.

THE SUCTION CATHETERA suction catheter should allow secretions to floweasily without damaging the mucosa. Suctioncatheters have a tendency to suck trachealmucosa into the catheter side holes, especiallywhile the catheter is stationary. This can causemucosal haemorrhage (Sackner et al 1973). It hasbeen shown that all suction catheters producesome degree of trauma, although it is often neg-ligible, during a single suction procedure and thatpoor or repeated suctioning techniques can causeincreased mucosal damage (Jung 1976, Regan1988, Kleiber et al 1988).

Multiple-eyed catheters have been shown tocause less damage than single-eyed catheters(Sackner et al 1973, Landa et al 1980, Sigler andWills 1985). This is because the multi-eyed typedissipate the focus of suction pressure, making itless likely that the mucosa will be sucked into theside holes. Many of the multi-eyed catheters havebeen designed to produce a cushion of air at thetip of the catheter in order to prevent the cathetercoming into contact with the tracheal mucosa,again causing less trauma (Sackner et al 1973,Serra 1982, Gibson 1983).Closed systems The closed system, multiple usesuction unit is designed to reduce the risk of cross

NOW DO TIME OUT 2

Based on what you have read so far, makeshort notes on your understanding of thecomplications of tracheostomy suctioning.

Using these notes, reflect on your past practice and identify areas whereimprovements should be made.

NOW DO TIME OUT 3

Before reading the next section, consider thesuction procedure that you are familiar withand add this to your notes for Time Out 2.

Box 2. How to calculatesuction catheter size

� Divide the tracheostomy tube’sinternal diameter by two – thisgives the external diameter ofthe suction catheter

� Multiply this result by three toobtain the French gauge (Fg)

For example, for a tracheostomytube with an internal diameter of8mm:

8 ÷ 2 = 4mm

4 x 3 = 12mm

The suction catheter size is 12Fg.

In addition, the diameter of thesuction catheter should be halfthe diameter of the tracheostomytube (DeCarle 1985)

Box 3. Tracheostomy tube and suction catheter sizes

TRACHEOSTOMY TUBE SUCTION CATHETER

IDmm Fg Fg ODmm

10 (30) (14) 4.59 (27) (14) 4.58 (24) (12) 4.07 (21) (10) 3.36 (18) (10) 3.35 (15) (8) 2.64 (12) (6) 2.03 (9) (5) 1.6

ID = Internal diameter; OD = Outer diameter; Fg = French gauge

52 NURSING STANDARD SEPTEMBER 30/VOLUME 13/NUMBER 2/1998

infection while suctioning (Fig. 1). It can also beused for patients who are ventilated, as ventilatorpressures can be maintained during suctioning ofthe critically ill patient.Calculating the size of the catheter To calculate thecorrect size of suction catheter use the formula inBox 2. The diameter of the suction cathetershould be half the diameter of the tracheostomytube (DeCarle 1985).

There is no standardisation of tracheostomytube and suction catheter sizes. It can be confus-ing, therefore, trying to work out what size ofcatheter to use for each size of tube. However, themajority of tracheostomy tubes are numbered byinternal diameter size and suction catheters arenumbered by Charriere (French gauge), althoughthey often include the outer diameter on the pack-aging (see Box 3).

COMMON QUESTIONS

Suction technique should ensure the maximumremoval of secretions, while causing no tissuedamage or hypoxia (Shekelton et al 1987).How long should suction last? Suction should beapplied for no longer than ten seconds (Brown1982, Serra 1982, DeCarle 1985, Martin 1989,Fiorentini 1992). Many older textbooksrecommend that suctioning should be carried outfor as long as you can hold your breath; however,this does not allow for the possibility that thepatient’s lungs are not healthy. The patient shouldbe encouraged to breathe deeply beforesuctioning commences and allowed time torecover between episodes. The length of recoverydepends on the individual patient and his or hersusceptibility to hypoxia.How far should the suction catheter be inserted? Again,this depends on the person being suctioned. Afew days after tracheostomy formation, mostpeople, unless ventilated, are able to coughsecretions to the end of the tracheostomy tubeand the suction catheter need only be inserted tojust beyond the end of the tube (approximately15cm).

Some textbooks state that the suction cathetershould be inserted until resistance is felt. This areaof resistance is called the carina, and is where thetrachea splits into the two bronchi. It is a sensitivearea of the trachea and causes coughing and dis-tress when touched. Research studies haveshown that the two main areas of tracheal trauma

are at the tip of the tracheostomy tube and at thecarina. This practice is no longer recommended(Kuzenski 1978, Serra 1982, DeCarle 1985, Siglerand Wills 1985, Kleibar et al 1988, Fiorentini 1992).Should the suction catheter be rotated on removal?Catheters are rotated in the belief that this will pickup more secretions and prevent adherence to thetracheal wall. Although this was the practice whensingle-eyed catheters were used, multi-eyedcatheters have holes around their diameter andcan, therefore, draw secretions without rotation.When should suction pressure be applied? Suctionpressure should only be applied when removingthe catheter. If pressure is on during insertion, thecatheter will adhere to the mucosa (Plum andDunning 1956).What about humidification? Breathing dry, cold aircauses the tracheal cilia to beat more slowly andsecretions to dry. It is important, therefore, tomaintain systemic hydration. If the patientbecomes dehydrated, the mucous membrane willbe drier, mucociliary transport will reduce andthere will be a retention of secretions.

Immediately following a tracheostomy, thepatient requires humidification to warm andmoisten inspired air. This should almost eliminatedried or tenacious secretions (Khan 1983, Doyleet al 1984, Ackerman 1985). After a few days, thetrachea adapts to the tracheostomy and secretionproduction is reduced (Sackner et al 1973, Lan-da et al 1980). This means that alternative humid-ification methods can be used.

HUMIDIFICATION Moist gauze veil This is simply a piece of moistgauze held in front of the tracheostomy by tapetied loosely around the neck. It provides bothmoist air and protection from inhalation of foreignbodies. It is useful in the initial period following atracheostomy, but in the long term it is notcosmetically the best solution. Many patients,however, continue to use it at night when at home.Tracheostomy covers There are many tracheostomycovers available, based on the use of foam. Someadhere to the skin above the tracheostomy tube,others tie around the neck. Moisture and warmthfrom expired air are trapped in the foam, andinspired air is warmed and humidified through thefoam.Heat and moisture exchangers These are cylindricaldevices that attach to the tracheostomy tube.They trap the warmth and moisture of expired airin a vast surface area created by rolled, oftencorrugated, paper at either end of the cylinder.Inspired air is warmed and humidified through therolled paper.Saline nebulisers These provide fully saturated airwith a fine mist of moisture for patients with a


NOW DO TIME OUT 4

Consider your healthcare environment. Do youknow what scale your suction pressure gauges

are and what type of suction catheters areavailable?

REFERENCESAckerman MH (1985) The use of bolus normal

saline installation in artificial airways: is ituseful or necessary? Heart and Lung. 14, 5,505-506.

Barnes C, Kirchhoff K (1986) Minimizing hypox-ia due to endotracheal suctioning: a reviewof the literature. Heart and Lung. 15, 2, 164-176.

Brown I (1982) Trach care? Take care – infec-tions on the prowl. Nursing. 6, 70-71.

Czornik R et al (1991) Differential effects ofcontinuous versus intermittent suction ontracheal tissue. Heart and Lung. 20, 2, 141-151.

DeCarle B (1985) Tracheostomy care. NursingTimes. 81, 40, 50-54.

Demers R, Saklad M (1973) Minimizing theharmful effects of mechanical aspiration.Heart and Lung. 2, 4, 542-545.

Doyle HJ et al (1984) Different humidificationsystems for high frequency jet ventilation.Critical Care Medicine. 12, 3, 815.

Fiorentini A (1992) Potential hazards of tracheo-bronchial suctioning. Intensive Critical CareNursing. 8, 4, 217-226.

Gibson IM (1983) Tracheostomy management.Nursing. 2, 18, 538.

Grossenbach-Landis I, McLane AM (1979)Tracheal suctioning: a tool for evaluationand learning needs assessment. NursingResearch. 28, 4, 237-242.

Harris RB, Hyman RB (1983) Clean v steriletrachy care and level of pulmonary infection.Nursing Research. 33, 2, 80-85.

Jackson c (1996) Humidification in the upperrespiratory tract: a physiological overview.Intensive and Critical Care Nursing. 12, 1,27-32.

Jung RC, Gottlieb LS (1976) Comparison of tra-cheobronchial suction catheters in humanchests. Chest. 69, 2, 179-181.

Khan RC (1983) Humidification of the airways,adequate for function and integrity. Chest.84, 4, 510.

Kleiber C et al (1988) Acute histologicalchanges in the tracheobronchial tree associ-ated with different suction catheter insertiontechniques. Heart and Lung. 17, 1, 10-14.

Knipper J (1984) Evaluation of a adventitioussounds as an indicator of the need for tra-cheal suctioning. Heart and Lung. 13, 3,292-293.

Kuzenski B (1978) Effect of negative pressureon tracheobronchial trauma. NursingResearch. 27, 4, 260-263.

Landa JF et al (1980) Effects of suctioning onmucociliary transport. Chest. 77, 2, 202-207.

Martin LK (1989) Management of the alteredairway in the head and neck cancer patient.Seminars in Oncology Nursing. 5, 3, 182-190.

Oermann MH et al (1983) After a tracheostomy:patients describe their sensations. CancerNursing. 16, 361-366.

Plum F, Dunning M (1956) Techniques for mini-mizing trauma to the tracheobronchial treeafter tracheostomy. The New EnglandJournal of Medicine. 254, 193-200.

Regan H (1988) Tracheal mucosal injury: thenurse’s role. Nursing. 3, 29, 1064-1066.

Sackner MA et al (1973) Pathogenesis and pre-vention of tracheobronchial damage withsuction procedures. Chest. 63, 3, 284-290.

Serra A (1982) Tracheostomy. Nursing Mirror.155, 2, i-xvi.


tracheostomy who either have dried secretions orfeel that their secretions are drying. Providinghumidification via a vapour or an aerosol hasbeen shown to thin secretions and promoteclearance (Demers and Saklad 1973, Sharpiro etal 1979).

CONCLUSIONThis article has discussed appropriate methods

for suction and humidification in patients who havea tracheostomy and, like any other procedure, anaseptic technique is of paramount importance.Time Out 5 reminds us that there is, of course, apatient involved in this procedure and that wemust not lose sight of that. Most nurses will, fromtime to time, manage a patient who has a tra-cheostomy, but the healthcare environments willvary enormously, for example in intensive careunits, on specialist ENT units, on general wardsand in the community. The needs of patients will,therefore, vary depending on whether the tra-cheostomy is to be temporary or permanent,whether the patient is conscious or unconscious,and whether the patient will be expected to man-age the suctioning him- or herself, or if a relativemay need to take on this responsibility. Havingstudied this article, you will be better informed andmore confident when advising patients, Box 4 pro-vides a summary of suctioning procedures �

NOW DO TIME OUT 5

Reflect on patients with a tracheostomy youhave nursed:

� How do you explain what is about to happen?� Do you use terminology that they do not

understand?� Do they ever appear anxious or irritated

when suctioning is being carried out?� For those who are going home with a

tracheostomy, how are they, or their relatives,taught to manage their own suctioning? You may find it helpful to discuss these

questions with a respiratory nurse specialist.Look back over the section that discussed

common questions that are often askedregarding tracheostomy suction and think ofhow you would respond to a patient asking

you the same questions.

Box 4. A tracheostomy suctioning procedure

� Assess for the need to suction� Explain the procedure to the patient, and what

he or she might feel� Turn on the suction pressure gauge, checking

that the pressure is set between 14 and 16kPa� Put on gloves� Attach the suction catheter to suction tubing.

Ensure the catheter is half the diameter of thetracheostomy tube

� Ask the patient to take a couple of deep breaths� Observe the patient at all times during the

procedure� With the Y-connector open (therefore no suction

pressure), insert the suction catheter into thetracheostomy tube until it is just beyond the endof the tube

� Apply suction pressure by covering the Y-connector

� Slowly withdraw the catheter, without rotation,within ten seconds

� Dispose of the suction catheter, following infection control procedures

� Repeat as necessary

Shekelton ME, Neild M (1987) Ineffective air-way clearance related to artificial airway.Nursing Clinics of North America. 22, 1,167-178.

Sharpiro B et al (1979) Humidity and aerosoltherapy. Clinical application of respiratorytherapy. Chicago Year Book. Chicago,Medical Publishers.

Sigler BA, Wills JM (1985) Nursing care of apatient with a tracheostomy. Tracheostomy.New York, Churchill Livingstone.

Skelley BFH et al (1980) The effectiveness oftwo preoxygenation methods to preventendotrachial suctioning hypoxia. Heart andLung. 9, 2, 316.

Van Oostdam JC et al (1986) Effect of breath-ing dry air on structure and function of air-ways. In: Fishman AP (Ed) Handbook ofPhysiology. Bethesda, Maryland, AmericanPhysiological Society. 312-317.

Documents

Tracheostomy Suctioning and Humidification