paediatric airwaymanagement

Best Practice & Research Clinical AnaesthesiologyVol. 19, No. 4, pp. 675–697, 2005

9

Airway management in infants and children

Ansgar M. Brambrink* MD, PhD

Associate Professor for Anesthesiolgy and Peri-Operative Medicine

Department of Anesthesiology and Peri-Operative Medicine, Oregon Health and Science University,

3181 SW Sam Jackson Park Road, Mail Code: UHS-2, Portland, OR 97239-3098, USA

Ulrich Braun MD, PhD

Professor Emeritus for Anesthesiology

Department of Anesthesiology, Rescue and Intensive Care Medicine, Georg-August-Universitaet Gottingen,

Universitaetsklinikum, D-37099 Gottingen, Germany

Anaesthesiologists, paediatricians, paediatric intensivists and emergency physicians are routinelychallenged with airway management in children and infants. There are important differences fromadult airway management as a result of specific features of paediatric anatomy and physiology, whichare more relevant the younger the child. In addition, a number of inherited and acquired pathologicalsyndromeshave significant impact on airway management in this age group. Several new devices—e.g.different types of laryngeal mask airways in various sizes, small fibre-endoscopes—have beenintroduced into clinical practice with the intention of improving airway management in this age group.Important new studies have gathered evidence about risks and benefits of certain confoundingvariables for airway problems and specific techniques for solving them. Airway-related morbidity andmortality in children and infants during the perioperative period are still high, and only a thorough riskdetermination prior to and continuous attention during the procedure can reduce these risks.Appropriate preparation of the available equipment and frequent training in management algorithmsfor all personnel involved appear to be very important.

Key words: children; neonates; airway management; paediatric anaesthesia; paediatric facemasks; conventional endotracheal intubation; cuffed endotracheal tubes; perioperative airwayrisks; laryngeal mask airway; laryngeal tube; fibre-optic intubation; paediatric fibre-endoscope;craniofacial malformations.

One key competence of an anaesthesiologist is securing the airway in patients of all agegroups. Anatomical and physiological differences between infants, children and adultsalso extend to the airway. Thus, airway management in younger patients requiresspecial expertise and familiarity with the equipment available. Of great concern are

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E-mail address: [email protected] (A.M. Brambrink).

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676 A. M. Brambrink and U. Braun

anatomical variations or pathological conditions of the airway, perhaps previouslyunrecognized in a young patient, which make routine airway management impossibleafter induction of anaesthesia or during emergency care.

There have been major improvements in this field over the years, such as theimplementation of the laryngeal mask airway (LMA) into the algorithms of routine anddifficult airway management in children, as well as the increasing availability of fibre-optic intubation even for infants. As of today, however, the routine airway in infants andthe management of expected and unexpected difficult airways in children of all ages stillpresent one of the major challenges to every anaesthesiologist, paediatrician andemergency physician.1

This chapter summarizes the anatomical and physiological characteristics of thepaediatric airway, provides an update of currently available paediatric airway equipment(including supraglottic airway devices and fibre-endoscopes in this age group), andexplains pathological conditions which are typically associated with a difficult airway inchildren and infants.

SPECIAL ANATOMICAL AND PHYSIOLOGICAL CONSIDERATIONS

Mature and premature newborns breathe exclusively through their noses, which mayresult in critical respiratory problems in children with, for example, bony or membranouschoanal atresia.2,3 The trachea length in preterm neonates is only 2–3 cm (25th and 35thweeks postconceptional age, respectively)4, and at term only 4 cm, and so a meticulouspositioning of the endotracheal tube is required to avoid endobronchial dislocation oraccidental extubation during subsequent manipulations etc. The position of the larynx isrelatively higher than that in adults; in the newborn, computed tomography (CT) ormagnetic resonance imaging (MRI) scans reveal the larynx at the C4 level5 as compared toC6–7 in the adult. This might be associated with difficulties during endotracheal intubation,especially in very young patients. Positional airway obstruction in unintubated neonatesmay occur in the supine position by posterocephalic displacement of the mandible, leadingto narrowing of the upper airway6 or, if intubated with an uncuffed endotracheal tube, byabutmentof the bevelled distal endotracheal tube orifice against the trachealwall.7 This canbe relatively easily prevented by providing appropriate neck and head support, such asfoam/gel rolls or cushions.

Newborns have an increased metabolic rate which results in a significantly greaterneed for oxygen than that in adults (6–7 mL/kg per minute versus 3–4 mL/kg perminute), leading to a decreased mixed venous return and a proportionally decreasedtolerance to apnoea. In addition, the residual capacity is much smaller at this age thanthat in the adult. The relation between alveolar ventilation (VA) and residual capacity(FRC) is 5:1 in newborns versus 1:1.5 in the adult, resulting in a significantly smallerrelative volume to store oxygen, e.g. prior to induction of anaesthesia. Even withadequate preoxygenation, arterial oxygenation (SaO2) may decrease below 90% evenafter 100 seconds in newborns, whereas in the same experimental setting school-agechildren kept their saturation above that level for at least 400 seconds.8 In clinicalpractice, optimal preoxygenation is often difficult to achieve (e.g. combative child withan air-tight face mask), and the risk for rapid desaturation is even higher. This requiresrapid and accurate airway management in this age group.

Newborns also produce CO2 at a much higher rate and require a higher alveolarventilation than adults (100–150 mL/kg per minute versus 60 mL/kg per minute). Dueto their small lung volumes, this can only be achieved by a significantly increasedrespiration rate (30–40/minute in newborn, 20–30/minute in infants).

Airway management in infants and children 677

The thorax of a newborn is bell-shaped and cartilaginous, and therefore much softerthan in the adult. The ribs are horizontally oriented, the epigastric angle is obtuse, andthe abdominal organs are relatively large. This does not allow for much extension of thediaphragm during ventilation with small airway pressures, and this, together with therelatively high lung compliance (0.06 mL/cmH2O in the newborn versus 0.04 mL in theadult), results in a higher risk of pulmonary overextension in newborns and infants, e.g.with manual ventilation during induction of anaesthesia.

Practice points

† newborns are exclusive nose-breathers, the larynx position is high, and thetrachea is short, all of which may result in difficulties in managing the airwayduring the perioperative period

† positional obstruction of the airway is more frequent in small children andinfants, and requires more emphasis on appropriate neck and head support

† increased metabolic rate, smaller relative volume to store oxygen, anddifficulties in providing optimal preoxygenation result in an overall higher riskfor critical desaturation during the perioperative period in young children; theyounger the child, the more concern should be applied, and the moreexperience is required to provide safe anaesthesia care

Research agenda

† to determine the incidence of critical desaturation and dangerous hypoxiccomplications during induction of anaesthesia in small children and infants inthe routine clinical setting (large multicentre studies are required)

† to evaluate the incidence of difficulties with mask-bag ventilation, trachealintubation and mechanical ventilation in small children and infants (similarly,voluminous studies would be beneficial)

FACE MASKS IN INFANTS AND CHILDREN

The face mask represents the simplest man-to-machine interface for oxygenating andventilating a patient. For adequate ventilation, the face mask should be of appropriatesize to allow for a perfect seal around mouth and nose, and the best-fitting mask needsto be determined for every child (Table 1). Successful ventilation using a face mask alsodepends on the optimal position of the patient’s head (e.g. the modified Jacksonposition allows for a stretch in the airway). Long-term face-mask ventilation carries asignificant risk for gastric insufflation, especially in the infant (see above).

Compared to the endotracheal tube, applying a face mask significantly increases deadspace. The smaller the patient, the greater this concern is. Randell–Baker/Soucek maskswere designed to minimize mechanical dead space according to the facial contours ofchildren.9 In addition, they are made of lightweight and transparent material, allowing forobservation of perioral skin colour and the humidity of the expired gases, and for theimmediate recognition of oral or gastric secretions. Children with anatomical or

Table 1. Oral airway and face masks for use in infants and children.

Age

Oral airway (Guedel tube) Face mask (Randell–Baker)

Size cm Size Dead space (mL)

Preterm 000 3.5 0 2

Neonate (0–3 months) 00 4.5 1 4

Infant (3–12 months) 0 5.5 1–2 4; 8

Toddler (1–5 years) 1 6.0 2 8

School age (5–12 years) 2 7.0 3 15

Teenager (O13 years) 3 8.0 n/a n/a

n/a, not applicable.


mechanical problems interfering with an appropriate face-to-mask seal (e.g. an oral-gastric feeding tube) may benefit from clear plastic masks with soft inflatable cuffs whichallow adaptation to the individual needs. If fibrescopic intubation is considered, a speciallydesigned clear plastic face mask provides an extra port which allows the passage of theendoscope while providing a means for oxygenation, ventilation and anaesthetic gasesduring the procedure.10 Alternatively, the Mainz universal airway adapter may be used.11

In young children, face masks are frequently used in conjunction with an oral airway,because their relatively large tongue may obstruct the airway during unconsciousness.Most commonly the smooth Guedel airway is used in children, but caution must betaken to use the proper size so as not to damage laryngeal structures or obstructvenous and lymphatic drainage, which may all result in postoperative airway swelling.12

In most cases, the appropriate size of oral airway for an individual child is equivalent tothe distance between the mouth and the angle of the mandible. Table 1 summarizesappropriately sized face masks and oral airways for the different age groups.

Practice points

† for every child the best-fitting mask needs to be determined on an individualbasis

† face masks increase dead space significantly; the smaller the patient, the greaterthe concern

† children with anatomical or mechanical facial abnormalities may benefit fromclear plastic masks with soft inflatable cuffs, which allow adaptation to theindividual’s needs

† specially designed clear plastic face masks are recommended for fibrescopicintubation

† oral airways may cause airway obstruction in the unconscious child due to therelatively large tongue

Research agenda

† to evaluate the incidence of difficult mask-bag ventilation in children† to evaluate the influence of positional changes and different face mask designs

on success with mask-bag ventilation in infants and small children


LARYNGEAL MASK AIRWAY

The laryngeal mask airway (LMA) was invented by A. I. J. Brain between 1980 and 1988,and was then released in the UK and later worldwide. The classic LMA was modified forspecial purposes according to the design criteria of the instrument. The flexible LMAwas available in 1992, the intubating LMA in 1997, the disposable LMA in 1998 and theProseal LMA in 2000. The inventor decided to try a scaled-down version of the adultLMA version for paediatric use. Today size 3 is considered a paediatric version. Thereare no paediatric sizes of the intubating or disposable LMAs. For paediatric applicationthe classic LMA is available in sizes 1, 1.5, 2, 2.5 and 3, the flexible LMA and the ProsealLMA in all sizes except 1 and 1.5. Most studies with more than 500 investigated childrenclaim that the LMA is safe and effective for children.13–18 It was a special experience tointroduce and observe the LMA in children. The non-invasiveness of the device wasvery convincing for an experienced anaesthesiologist for whom coughing belonged toanaesthesia like pain to surgery.

Before insertion of the LMA, preoxygenation should be provided. Propofol is asuitable induction agent for children, but the dose is much higher than in adults.Unpremedicated children require at least 4 mg/kg (rather than 2 mg/kg in the adultpatient) and the dose should be titrated according to the clinical response.19 The targetpropofol concentrations are in the range of 8–14 mg/mL in children, compared to 6–10 mg/mL in adults.19 Propofol and sevoflurane provide similar induction conditions, buthypotension may be more common after propofol.19 Data in the literature suggest thatanalgesic coinduction agents facilitate LMA insertion.

The original Brain insertion technique as described in 198320 is recommended, andcan be used for the classic, the disposable and the flexible LMA. The deflated cuff isintroduced by placing the head and neck in the usual intubating position and applyingpressure on the hard palate with the finger-pencil grip. The instrument is movedforward in the midline after lubrication. Variations of the original insertion techniqueare the lateral approach and the thumb technique. The original Brain technique issuccessful in a very high percentage of all cases, but on the other hand there is noevidence up to now that it guarantees a higher rate of correct positioning thanalternative techniques. Therefore partial filling of the cuff and laryngoscope-guidedinsertion may be used if the classical technique fails. For the Proseal LMA laryngoscopeguidance can be advocated by mounting the LMA on a gastric tube (GT), introducingthe GT with the laryngoscope and letting the LMA slip in place via the GT. Thistechnique is very promising for the Proseal LMA because it provides a forwardmovement into a good position by using a railroad. Cuff inflation should be providedwith the minimal volume to form an effective seal. Bite blocks are recommended exceptfor the Proseal LMA, which has an integrated bite block.

Oropharyngeal leak pressure is around 20 cmH2O in children.19 Haemodynamicresponses are lower for LMA insertion than for conventional laryngoscopic trachealintubation.19 Airway-protective reflex activation with the LMA is not as frequent aswith tracheal intubation.19

Medical imaging studies and case reports suggest that the LMA is frequently poorlypositioned in children but gas exchange is unaffected.21–24 The use of muscularrelaxation is not mandatory. Spontaneous ventilation and positive-pressure ventilationare both used extensively in children. It is important to avoid superficial levels ofanaesthesia, because the larynx can always go into spasm at surgical or otherstimulations. In theory, removal of the LMA should be preferred awake, after the


reflexes such as swallowing reappear. In practice, investigators have shown that thereare no differences between awake and deep removal25,26, and that deep removal causesless coughing and less hypoxia.27–30

The LMA may be applied for difficult airway problems and for resuscitation, where itis effective in normal and low-birth-weight neonates19, but it may also be applied in thenormal paediatric population.

There may be more complications in infants and neonates if the LMA is applied foranaesthesia. The success rate of correct placement is lower than in older children, andgastric insufflation and laryngospasm are more frequent.19 This may be due toanatomical differences and to the fact that a deep level of anaesthesia is necessary andmuch more difficult to reach and maintain than in older children.

The LMA can be used for cardiovascular and urological examination, dental surgery,endoscopy (tracheobronchoscopy, gastroscopy), ENT, general, orthopaedic or plasticsurgery, ophthalmic surgery, medical imaging, radiotherapy and interventional radiologyand tracheostomy.19

Other supraglottic airway devices have been devised for paediatric use, also with allpaediatric sizes available. These are the soft-seal laryngeal mask (Portex, UK) and thelaryngeal tube airway (VBM, Germany). There are no studies yet on either of these. Thecuffed oropharyngeal airway (COPA, Mallinchrodt Medical, Ireland) was studied for usein paediatric patients19, but the device has been withdrawn by the manufacturer and isno longer available for clinical use. More studies are required to find out whether thealternative paediatric oropharyngeal airways other than the LMA are safe and effectivefor clinical use.

Practice points

† LMAs are now available for all age groups† LMA placement in children is facilitated by using propofol and an appropriate

dose of an analgesic drug for induction of anaesthesia; the classical insertiontechnique is recommended

† the Proseal LMA is easily placed using a laryngoscope and after mounting theLMA onto a gastric tube; it is now available for almost all age groups

† the LMA is frequently badly positioned in younger children, but gas exchange isunaffected; complications have been reported more frequently when the LMAis used in infants

† the LMA may be applied for various situations involving a difficult airway inchildren and during resuscitation, e.g. in infants

† alternative supraglottic airway devices for use in children and infants are thesoft-seal laryngeal mask and the laryngeal tube airway

Research agenda

† to determine the applicability and safety of alternative supraglottic airwaydevices when used in small children and infants


CONVENTIONAL ENDOTRACHEAL INTUBATION IN PAEDIATRICPATIENTS

The list of indications for an endotracheal intubation in children is similar to that foradults, i.e. endotracheal intubation is considered the gold standard for protecting theairway from aspiration, assuring adequate ventilation in the critically ill child (e.g. withpneumonia), and securing the airway during emergencies. Endotracheal intubation maybe beneficial for infants as they are more likely to develop upper airway obstruction andgastric distention with longer periods of mask ventilation than are older children.(Detailed descriptions of standard equipment and techniques are available in therelevant chapters in current text books.31–33) However, laryngospasm or bronchos-pasm, airway oedema and postoperative tracheal stenosis have been associated withendotracheal intubation, especially in young children, and the potential risk factorsrequire careful consideration. Areas of concern are the child’s current medicalcondition, materials used, co-medication, and the work environment in which airwaymanagement is performed.

Upper respiratory tract infection (URTI)

There is increasing evidence to suggest that children with URTIs carry an increased riskfor respiratory complications when endotracheal intubation is performed.34–45

Additional risk factors include second-hand smoke, nasal congestions, copioussecretions and productive cough, history of reactive airway disease, prematurity,snoring, surgery involving the airway, and anaesthetic technique (thiopental, residualmuscle relaxant activity36,37). Even though the more severe complications—e.g.laryngospasm or bronchospasm—are rare, and a direct association remainscontroversial36,37, less severe complications seem to occur two to three times morefrequently following endotracheal intubation in children with URTI for a period of atleast 4 weeks after the infection.36,41,42,44 However, surgery may be performed even asan outpatient procedure if an experienced anaesthesiologist is providing perioperativecare.34 If suitable for the procedure, these children may benefit from the use of an LMAfor perioperative airway management.38,46 Regardless of these means, the elevatedrisks must be weighed on an individual basis against the potential benefit of a 4-weeksurgery delay, and should be discussed in detail with parents and surgeons.

Endotracheal tube size

The endotracheal tube itself poses resistance to airflow which is inversely proportionalto the fourth power of the radius and directly proportional to the length, i.e. thenarrower and longer the tube, the larger the flow resistance. This is of significantclinical importance for children during anaesthesia or intensive care, and ideally wouldrequire the widest and shortest possible breathing tube to be placed into the trachea.However, a child’s trachea is small, and its smallest diameter is at the level of the ringcartilage (cricoid ring), making it more funnel-shaped than an adult’s, and the narrowestaspect cannot been seen during conventional laryngoscopy. A tightly fittingendotracheal tube can easily result in decreased mucosal perfusion and subsequentoedema. The younger the child, the smaller the degree of subglottic oedema whichalready may result in critical airway obstruction and associated syndromes, e.g.dyspnoea, hypoxaemia, anxiety/panic, and the potential need for invasive management.


Finally, even cartilage damage may occur, potentially resulting in life-long impairmentand disability, although no study has proved an association. Selection of the correctlysized endotracheal tube is facilitated by several formulae, the most widely accepted ofwhich is related to the age of the child (inner diameter [ID] in mmZ(16Cage in years)/447,48, which was modified to: ID in mmZ(age in years/4)C4.49 This calculationoverestimates the correct size in more than one in four cases50, meaning that it isnecessary to have a one-size-smaller tube available at all times. Others have suggested amore conservative formula—ID in mmZ(age in years/4)C3.5—which may in factresult in a higher incidence of selections of tubes which are too small.31 Someemergency physicians and paramedics calculate tube size according to the height of thechild (e.g. Broselow tape), which results in a similar predictive value (55% correct), butin contrast an erroneous prediction usually results in a smaller tube, which implies areduced risk for airway injury.51 Current recommendations to determine the correctsize of cuffed endotracheal tubes for children again relate to age. Either the standardformula (above) is applied and the predicted inner diameter size is reduced by 0.5 or1.0 mm, or adapted formulae are used: e.g. ID in mmZ(age in years/4)C3.49 However,selecting the correct tube size in children may be much more complex, leading othersto propose a multivariant prediction model represented by the formula 2.44C(age!0.1)C(height!0.02)C(weight!0.016).52 A meticulous study recently suggested thatnone of the above-mentioned formulae seems able to predict the optimal size ofendotracheal tube (uncuffed or cuffed) correctly. Among other reasons, the authorsfound a high product variability with regard to the outer diameter at a given internaldiameter between different manufacturers and designs.53 In addition, the above-mentioned calculations cannot be applied to children under the age of 2 years, andappropriately sized endotracheal tubes for infants and newborns must be chosenaccording to specified suggestions from the literature (see Table 2). Airway resistance

Table 2. Recommendations for endotracheal tube size and positioning in infants and children.

Age

Internal diameter

(mm)aGums/distance between inci-

sors and mid-trachea (cm)bDistance between nostril

and mid-trachea (cm)c

Premature 2.0–3.0 6–8 7–9

Newborn 3.0–3.5 9–10 10–11

3–9 months 3.5–4.0 11–12 11–13

9–18 months 4.0–4.5 12–13 14–15

1.5–3 years 4.5–5.0 12–14 16–17

4–5 years 5.0–5.5 14–16 18–19

6–7 years 5.5–6.0 16–18 19–20

8–10 years 6.0–6.5 (cuffed; 1.0)d 17–19 21–23

11–13 years 6.0–7.0 (cuffed; 1.0)d 18–21 22–25

14–16 years 7.0–7.5 (cuffed; 1.0)d 20–22 24–25

However, the appropriate endotracheal tube size for the individual child will vary according to age, height,

weight, specific anatomical variations and ventilatory requirements; for most clinical situations, an air leak

of 15–30 cmH2O is recommended. Modified from Finucane and Santora (2003, Principles of Airway

Management 3rd edition, New York, Berlin: Springer, p. 395) with permission. Suggestions according to the

formulae in children O2 years of age:a Uncuffed endotracheal tube, internal diameter (ID) in mmZ(age in years/4)C4.b Oral–tracheal distance in cmZ12C(age/2).c Naso–tracheal distance in cmZ15C(age/2).d Cuffed endotracheal tube, ID in mmZ(age in years/4)C3.


and flow characteristics can be improved significantly if the endotracheal tube isshortened, for example if a smaller-than-desired tube must be used.54

In the environment of anaesthesia, the size of the endotracheal tube appears to beless of a problem if children are ventilated using an anaesthesia machine. However, withthe need for increasing the respiratory rate, the delivered tidal volume may decrease,thereby preventing a linear increase in minute volume. Interestingly, endotracheal tubesize seems to matter more in children with normal lung compliance for the minutevolume in relation to the peak inflation pressure, whereas in those with low compliancethe lung appears to be the main determinant of delivered ventilation.55

Cuffed versus uncuffed endotracheal tubes

Cuffed endotracheal tubes have not been advocated for use in children under the age of8 years until recently. The key concern has always been that the inflated cuff poses anadditional and unnecessary risk for both irritation and potentially ischaemia of thetracheal mucosa and the underlying soft tissue, with the same dangerous and possiblydevastating consequences as described above for snug-fitting uncuffed endotrachealtubes. Some of these effects may in fact be related to the apparent poor design of mostcurrently available cuffed endotracheal tubes, as recently demonstrated.53 Clinicianshave also argued that the uncuffed endotracheal tube provides a larger inner diameterfor a given outer dimension, thereby reducing resistance while improving laminar flowcharacteristics (see above), allowing a larger range to adapt to the respiratory needs,especially in the young child and infant. On the contrary, cuffed endotracheal tubes havebeen proposed by others to be advantageous even in small children for a number ofreasons—e.g. to reduce the number of intubation attempts—because a potential leakdue to a smaller (than for age) tube can be accommodated by the inflation of the cuff toachieve an appropriate airway seal. Additional valid reasons may be the reduction ofanaesthetic gas contamination in the work environment, the option of providing low orminimal-flow anaesthesia or high-pressure ventilation and respective monitoring in, e.g.newborns with non-compliant lungs, and the reduction in risk for perioperativetracheal aspiration. Scientific proof, however, is lacking for all of the above (for reviewsee reference 35). Recent studies have shown that the use of cuffed tubes is notassociated with a higher incidence of respiratory complications in young children49,56,57

or infants.58 Despite these results, cuffed endotracheal tubes are not widely acceptedamong clinicians in different countries, and are in fact discouraged by several specialistgroups in Europe.35,59,60 If cuffed endotracheal tubes are used in young children orinfants, the cuff pressure should be monitored continuously, especially if nitrous oxide isused.60,61 Whether an air leak at, e.g. 20–25 cmH2O may be a sufficient substituteneeds to be determined in future studies.62 A recently introduced paediatric trachealtube with a so-called high-volume, low-pressure polyurethane cuff seems to bepromising and may prompt a re-evaluation of current recommendations for the use ofcuffed endotracheal tubes in children and infants.63

Placement of an endotracheal tube without muscle relaxants

Endotracheal intubation can be achieved in children without muscle relaxant if desired. Arecent multicentre survey64 showed good intubation conditions with inhalationalsevoflurane (end-tidal concentration 5.9G1.5 vol%) in 97% of the children comparedwith 71% with intravenous propofol (5.8G4.2 mg/kg), which was slightly improved by the


concomitant use of opioids. Infants required higher sevoflurane concentrations forsuccessful endotracheal intubation. The success rate at first attempt was also lower, andthe peripheral oxygen saturation decreased more frequently than in older children. Theauthors found no difference in stridor on extubation between children intubated withcuffed (l.4%) or uncuffed (2.7%) tubes. These results indicate the need for a thoroughevaluation of risks and benefits of muscle relaxation for intubation, especially in infants.

Endotracheal intubation prior to transportation and in an out-of-hospitalsetting

As of today it still is undetermined whether, among other patient groups, children benefitfrom endotracheal intubation in the field.65 A retrospective study documented animproved survival rate of children with severe blunt head traumas who receivedendotracheal intubation by emergency physicians at the scene;66 however, a large andwidely recognized prospective study (830 consecutive patients, age 12 years or younger,all emergencies requiring ventilation) revealed that endotracheal intubation performedby paramedics in the field showed no effect on survival and neurological outcomecompared with bag-valve-mask ventilation.67 With regard to possible complications, theauthors conclude that the common practice of paramedics intubating children isquestionable. Children in hospitals who need endotracheal intubation prior to transportmay also be at risk; a prospective study of airway management in 250 children beforetransport to an intensive care unit found that anticholinergic agents were giveninfrequently, some patients received only neuromuscular blocking agents withoutsedation, and inappropriately sized endotracheal tubes were used.68 The increasednecessity for qualified out-of-hospital care in children requires immediate efforts toanalyse risks and benefits as well as potential means for improvement of airwaymanagement in children and infants either in the field or during transport.

Practice points

† endotracheal intubation is considered the gold standard to protect the airwayin the critically ill child

† children with upper respiratory tract infections carry an increased risk forrespiratory complications with endotracheal intubation; however, anaesthesiacan be considered safe when performed by an experienced anaesthesiologist

† the resistance to airflow caused by the endotracheal tube is inverselyproportional to the fourth power of its radius and directly proportional to itslength, i.e. the narrower and longer the tube, the larger the flow resistance

† tight-fitting endotracheal tubes may result in mucosal oedema; the younger thechild, the smaller the degree of subglottic oedema necessary to cause criticalairway obstruction

† most widely accepted formula to determine the correct size of an uncuffedendotracheal tube relates to the age of the child: inner diameter in mmZ(16Cagein years)/4

† only recently, cuffed endotracheal tubes have been advocated for the use inchildren under the age of 8 years; they should only be used in this age group ifthe cuff pressure is monitored continuously

† if desired, endotracheal intubation can be achieved in children without musclerelaxant

Research agenda

† to identify and validate appropriate screening systems to predict a difficultairway in young children and infants

† to determine whether children benefit from endotracheal intubation duringemergency trauma care in the field

† to determine whether critically ill children benefit from endotracheal


intubation for interhospital transfer

TRACHEAL INTUBATION OF INFANTS AND CHILDREN USINGFIBRE-ENDOSCOPES

If conventional laryngoscopy does not allow for sufficient viewing of laryngealstructures, alternative techniques are necessary. This may include the application ofdifferent laryngoscope blades69,70, modified laryngoscopes (e.g. McCoy71, Bullard72),and the use of flexible or rigid fibrescopes.

In several institutions, fibre-optic intubation of the trachea in children and infants with adifficult airway is performed under conscious sedation and maintenance of spontaneousventilation.35,73 This procedure provides continuous oxygenation during tube placement,even if the procedure is more difficult than expected and requires additional manoeuvresor a second, more experienced operator to be successful. The regimen includesappropriate doses of benzodiazepines, ketamine, opioids or propofol according to thepreference of the responsible physician, always sufficient topical anaesthesia of the mouth/nose, pharynx, larynx and trachea using, e.g. 1–2% lidocaine (maximum 4.5 mg/kg topically,allowing 1–2 minutes to act) or similar techniques74, as well as appropriate monitoring andcontinuous oxygen insufflation (e.g. via the endoscope). Alternatively, tracheal intubationcan be achieved after induction of general anaesthesia either intravenously or byinhalation.75 As a general rule, and similarly to adult patients, the operator needs to be fullyconfident that the child can be ventilated using a face mask or an appropriate supraglotticairway device (e.g. LMA, plan B) if endoscopic intubation of the trachea is intended undergeneral anaesthesia. Several reports have been recently published about the use of an LMAas a conduit for successful endoscopic intubation of the trachea under general anaesthesiain this age group76–79, which appears to be an excellent choice for children with preciselydocumented mild to moderate airway abnormalities or limitations for conventionallaryngoscopy (e.g. spine injury or facial burns).

Flexible endoscopes for paediatric endotracheal intubation

Appropriately sized instruments are available from different suppliers: e.g. Olympus, Pentax,Karl Storz (Table 3). Problems may occur in newborns and infants requiring endotrachealtubes size 3.0 or lower. In these patients, very small (‘ultra-thin’) flexible fibrescopes have tobe used, but only one of the above-mentioned fibrescopes (Karl Storz, 2.8 mm outerdiameter) provides a working channel for the application of topical anaesthesia, continuousoxygen flow or suction. The outer surface of this instrument has recently been redesigned(sandblasted) and fits a 3.0 tube forover-the-scope endotracheal intubation. However, evenwith the availabilityof this instrument, theplacementof smaller tubes—e.g. 2.5 mm ID—stillremains a challenge. For this situation, a ‘two-different-sizes bronchoscope technique’ has

Table 3. Flexible fibrescopes for endotracheal intubation in infants and children.

Manufacturer

Endoscope (outer diameter in

mm)

Instrument channel (inner

diameter in mm)

Olympus (Olympus Europa

GmbH, Hamburg, Germany)

4.0 1.5

3.6 1.2

2.2 None

Pentax (Pentax Medical Com-

pany, Montvale, NJ, USA)

3.1 1.2

2.4 None

Karl Storz (Karl Storz GmbH &

Co. KG, Tuttlingen, Germany)

3.7 1.5

2.8 1.2


been suggested80, described first by Kleemann et al81: a small bronchoscope (e.g. theOlympus 2.2 mm outer diameter) carries the endotracheal tube (e.g. 2.5 mm innerdiameter), while the biopsy channel of a second (larger) one allows the application of topicalanaesthesia and the continuous flow of oxygen during most of the procedure.

Rigid fibrescopes for endotracheal intubation in infants and children

Rigid or semi-rigid bronchoscopes are even less frequently used in infants and childrenthan in adults. Most available equipment has been designed for use in adult patients: e.g.Bonfils82, Upsher Scope, and Wu Scope (the last two are virtually laryngoscope/bronchoscope hybrids). Only a few such devices have been used in small children: e.g.the Shikani Optical Stylet.83 The experienced operator has an improved view of theairway structures, and endotracheal intubation is facilitated—especially in patients witha difficult anatomy. Rigid bronchoscopes are generally less expensive to acquire andmaintain than flexible endoscopes, and some clinicians consider them easier to use thanthe latter after having achieved sufficient training with the particular rigid technique.84

Others have introduced two different semi-flexible miniature scopes (outerdiameter 2.0 mm) specially designed for use in infants and small children.85,86 Specialadapters allow for the adjustment of the various lengths of paediatric endotrachealtubes, as well as continuous oxygen administration alongside the scope through thelumen of the endotracheal tube. The first systematic clinical evaluation of one of thenew devices showed a significantly better visualization of the larynx and vocal cords andexcellent success with tracheal intubation.87

Endotracheal intubation using a rigid fibrescope is typically considered to requiregeneral anaesthesia by either intravenous or inhalation technique. This would excludethe application of these devices in children with a difficult airway which has notpreviously been fully evaluated and may present an airway obstacle to a straight tubeplacement, or which may pose a risk for unexpected anatomical changes since the lastprocedure. In these cases fibre-optic intubation using a flexible endoscope underadequate sedation appears to be safer for the child.

Video-assisted systems for endoscopic airway management in childrenand infants

In our opinion, video-assisted systems for endotracheal intubation will gain morepopularity in paediatric anaesthesia due to the large image on the TV screen which can be


seen with both eyes, and without having to adapt to the operator’s vision.88,89

Additionally, because assistance during the intubation procedure is essential (e.g.pressure on the larynx, chin lift, advancement of the endotracheal tube providinganaesthesia), these tasks can be carried out much more efficiently using a video display.Finally, video-assisted intubation appears to be an excellent teaching tool, as theattending anaesthesiologist can demonstrate the procedure to the resident or student aswell as precisely observe and correct the procedure when performed by the resident, ashas recently been proved by a systematic analysis.90 Some novel devices seem to beparticularly promising. Two different semi-flexible miniature video neonatal intubatingscopes (outer diameter 2.0 mm) have been introduced, both of which are equipped withintegrated DCI TV cameras and special adapters to adjust the various lengths ofendotracheal tubes and allow for simultaneous oxygen administration alongside thescope through the tube.85,86 One of these scopes has been evaluated in a largermulticentre trial.87 Another recently developed video laryngoscope (Acutronic MedicalSystems AG, Hirzel, Switzerland) was used to intubate the trachea in patients with PierreRobin sequence.91 Integration of very small TV cameras into the handle of flexiblefibrescopes results in an always-ready-to-use system for video-guided fibre-opticintubation of the trachea in infants and children.92,93 Finally, the concept of a specialairway management cart appears to facilitate manipulation and observation during fibre-optic intubation: the TV monitor is mounted on a swivel arm containing the cameracontrol unit, light source and videotape recorder. This allows for the projection of thevideo image above the patient’s chest.85

Practice points

† as in adults, fibre-optic tracheal intubation in children and infants can beachieved under conscious sedation and maintenance of spontaneousventilation; alternatively, fibre-optic tube placement may be performed afterinduction of general anaesthesia if it is known that the child can be oxygenatedusing mask-bag ventilation

† the LMA can be helpful as a conduit to guide endoscopic intubation† appropriately sized instruments are available from different suppliers; consider

the ‘two-different-sizes bronchoscope technique’ if necessary† rigid bronchoscopes are less frequently used in young children; their use

typically requires general anaesthesia prior to airway management† video-assisted systems for endotracheal intubation allow observation of the

procedure with both eyes (video image and the ‘outside’ at the same time);they do not require vision adaptation, improve assistance during theprocedure, and provide excellent teaching opportunities

PATHOLOGICAL CONDITIONS

Various craniofacial abnormalities arise from maldevelopment of the first and secondvisceral arches which form the facial bones and ears during the second month ofgestation. These malformations include cleft lip and cleft palate, Treacher–Collins(synonym in Europe: Franceschetti), Goldenhar, Pierre Robin and Nager syndromes.Children with these malformations have normal intelligence.


Treacher–Collins syndrome is also called mandibulofacial dysostosis. It includesmalformed external ear, malar and mandibular hypoplasia, anti-mongoloid slanting,palpebral fissures, coloboma of lower eyelid, and conductive hearing loss.

Goldenhar syndrome (oculo-auriculo-vertebral dysplasia) shows facial asymmetryunique to this syndrome, microphthalmia, epibulbar lipodermoid, malformed externalear, conductive hearing loss, macrostomia and mandibular hypoplasia.

Pierre Robin (PR) syndrome is rather named PR sequence today, because beside thetypical features other malformations are combined with it in a variable way. The typicalmalformations are micrognathia with glossoptosis and cleft soft palate.

The Nager syndrome is also called acrofacial dysostosis. It includes mandibular andvelum hypoplasia and thumb dysplasia or aplasia. Eye and ear anomalies may be present.

Depending on the severity of the anatomical changes, noisy breathing, airwayobstruction and feeding problems may arise. Some malformations are so severe thatthe children die at an early age. Mandibular hypoplasia is prevalent in many of theaforementioned malformations. It can contribute to airway obstruction and feedingproblems, as in the Nager syndrome.94

Mandibular hypoplasia is a frequent feature of craniofacial malformations. It may betreated with mandibular distraction osteogenesis. With this rather non-invasive approachthe mandible can grow after double osteotomy and fixation of a bidirectional distractor.95

Severe symptoms of airway obstruction may be relieved in infants and small children.Mucopolysaccharidosis (MPS) is caused by a specific genetic enzyme defect and has

distinct clinical features, a predictable prognosis, increased urinary mucopolysaccharide

Figure 1. Franceschetti syndrome.


excretion, and variable systemic manifestations. Among these a typical facialappearance, corneal opacity, skeletal dysplasia, mental deficiency, hepatosplenomegalyand severe airway problems may be observed.96,97 Today there are seven subtypes ofthe disease, MPS I–VII, number VI with types A and B. The Hurler description is type I.Patients with this disease usually do not reach the age of 10 years.

Noma (cancrum oris) is an acquired infectious disease associated with poverty andmalnutrition in sub-Saharan African and South American regions.98 It is an orofacialgangrene arising as the result of a rapidly spreading opportunistic infection caused by thenormal oral flora. Most children die in the acute phase; only around 10% survive. They areleft with facial and bony destruction which leaves major scars, open nasal and oral cavitiesand trismus. At that stage surgery may improve the patient situation with reconstructiveplastic and maxillofacial interventions. Treatment of the acute phase with infusions andantibiotics is successful provided that the children do not reach the hospital too late.

Some years ago we were faced with an 11-year-old very small boy withFranceschetti syndrome and phocomelia who could not be intubated for dentaltreatment (Figure 1). After providing a flexible endoscope with a diameter of3.6 mm, we put the patient to sleep with spontaneous ventilation under halothane.The problem was to keep the anaesthetic level and spontaneous breathing stable. Itwas difficult to visualize the larynx because of a very narrow pharynx and the gravityeffect in the supine position. Intubation was successful after 40 minutes, and surgeryand anaesthesia were uneventful. This was a key experience for the management of

Figure 2. Goldenhar syndrome.


the difficult airway and made us follow that clinical path. We preferred inhalationalanaesthesia with halothane or sevoflurane and spontaneous ventilation if fibre-opticintubation was indicated. It is essential to reach a deep level of anaesthesia and tokeep spontaneous ventilation well preserved. We also used ketamine andbenzodiazepines, but our experience was that it is not possible to reach a deeperlevel of anaesthesia with less protective reflex activity and to avoid laryngospasm.We have applied LMA successfully in Goldenhar syndrome99, Pierre Robin sequenceand Nager syndrome when intubation was not indicated (Figures 2–4). This isconfirmed by an overview of the literature19 and is also applicable to the Treacher–Collins (Franceschetti) syndrome. We performed a fibre-optic intubation via theLMA if there was an indication for it. In infants and small children, only the standardversion of the LMA (classic) could be applied. The flexible LMA is very useful foranaesthesia, but not for fibre-optic intubation. Today the Proseal LMA may be evenmore appropriate for anaesthesia in this patient group.

Mucopolysaccharidosis (MPS) warrants a different airway approach from that in thecraniofacial malformations. We have anaesthetized six male patients with this syndromebetween 3 and 42 years of age (type I, Figure 5, type II, two cases, type IV, and type VI, twocases). The severity of the course of the disease depends upon the type of enzyme defect.

Figure 3. Pierre Robin sequence.

Figure 4. Nager syndrome with distractor.


Type I (Hurler) is the most symptomatic MPS class. All patients had to be intubated forminoror moderate surgical interventions. The oldest patient with a type IV disease couldbe intubated conventionally with ease. All others needed a fibre-optic intubation via theLMA. In one we performed an awake procedure after topical anaesthesia in the sittingposition (14 years of age); in all others the LMA and the tracheal tube were positionedunder intravenous or inhalational anaesthesia. Face-mask ventilation was possible whenit was needed. Selection of LMA size was difficult. Placement of the LMA may or may notbe successful. Change in positioning of head and neck and tongue manipulation may benecessary. There are extensive anatomical variations around the larynx.

One of the authors (UB) took part in a team effort to treat 37 noma patients inNigeria in the year 2000, many of which were children (Figure 6). In these patients theface mask and the LMA cannot be applied, and a fibre-optic intubation technique has tobe used. The tolerance for the awake fibre-optic was better than that in Europe. Thepatients cooperated from the age of 12 years and above; younger patients receivedhalothane. Spontaneous ventilation was preserved. There was a 100% success rate withfibre-optic intubation, in one case after a second attempt.

From our experience we can summarize that tracheal intubation is difficult in all ofthe mentioned patient groups. The laryngeal mask is a very effective airway tool forcraniofacial malformations, much less so for the mucopolysaccharidoses, and is notapplicable in noma patients. The face mask may or may not work in craniofacialdisorders and MPS and is not effective for the noma group. It is important to preserve

Figure 5. Mucopolysaccharidosis (MPS) type Hurler.


consciousness and/or spontaneous ventilation if very difficult airway conditions aremet. The decision to anaesthetize should be taken only if face mask or LMA ventilationcan be provided safely. If these conditions are not known, fibre-optic intubation underspontaneous ventilation is the only secure approach.

Practice points

† several craniofacial abnormalities occur early during pregnancy (2nd gestationalmonth)

† others are acquired during childhood and may result from various causes, e.g.metabolic or infectious diseases

SUMMARY

Airway management in children and infants, especially in those with a difficult airway,presents a major challenge for every anaesthesiologist, paediatrician, paediatric

Figure 6. Noma: (a) preoperative, and (b) postoperative.


intensivist and emergency physician. The most important differences, as compared toadult airway management, result from the specific aspects of paediatric anatomy andphysiology, which are more important to consider the younger the child is. A number ofinherited and acquired pathological syndromes have significant impact on the airwaymanagement in this age group. During past years several new devices have beenintroduced into clinical practice, intended to improve airway management in this agegroup. Important new studies have gathered evidence about risks and benefits of certainconfounding variables for airway problems and specific techniques for solving them.

Several risk factors for airway-related problems during anaesthesia in children havinga ‘cold’ have been identified, and the use of propofol in combination with the LMA issuggested if anaesthesia cannot be postponed in children with a recent upper airwayinfection. The use of cuffed endotracheal tubes appears to be advantageous in certainclinical situations, and may be safe in infants if the appropriate tube size is carefullydetermined and continuous monitoring of the cuff pressure is performed to avoidpost-intubation tracheal stenosis. Promising novel video-assisted systems comprisingappropriately sized and redesigned fibre-optic endoscopes have been introduced forthe management of the difficult airway in small children, infants and even prematurenewborns. Today, the laryngeal mask airway is a well-accepted extra-tracheal airwaydevice in paediatric anaesthesia, and the flexible LMA allows for its use during ENTanddental surgery procedures. However, LMA-associated partial obstruction of the airwayin infants requires great caution when these devices are used in this age group. Therecently introduced Proseal LMA for children may allow higher airway pressures andimproved protection from gastric inflation, e.g. in paediatric ambulatory anaesthesia.The LMA may also serve well to guide the endoscope during fibre-optic intubation inchildren and infants.

Prediction of the unexpected difficult airway in infants and children remainsreally difficult, as the respective screening systems have been developed in adults

*


and are, for a variety of reasons, not applicable to young children and infants. Athorough determination of the individual risk of developing airway complications, aswell as continuous attention to airway patency during the procedure, areprerequisites for reducing airway-related morbidity and mortality in children andinfants during anaesthesia. Appropriate preparation of the available equipment andfrequent training in management algorithms for all personnel involved appear to bevery important.

REFERENCES

*1. Morray JP, Geiduschek JM, Ramamoorthy C et al. Anesthesia-related cardiac arrest in children: initial

findings of the Pediatric Perioperative Cardiac Arrest (POCA) registry. Anesthesiology 2000; 93: 6–14.

2. Issekutz KA, Graham Jr. JM & Prasad C. An epidemiological analysis of CHARGE syndrome: preliminary

results from a Canadian study. American Journal of Medical Genetics A 2005; 133: 309–317.

3. Brown OE, Pownell P & Manning SC. Choanal atresia: a new anatomic classification and clinical

management applications. Laryngoscope 1996; 106: 97–101.

4. De Dooy J, Ieven M, Stevens W et al. Endotracheal colonization at birth is associated with a pathogen-

dependent pro- and anti-inflammatory cytokine response in ventilated preterm infants: a prospective

cohort study. Pediatric Research 2004; 56: 547–552.

5. Hudgins PA, Siegel J, Jacobs I & Abramowsky CR. The normal pediatric larynx on CT and MR. American

Journal of Neuroradiology 1997; 18: 239–245.

6. Tonkin SL, McIntosh CG, Hadden W et al. Simple car seat insert to prevent upper airway narrowing in

preterm infants: a pilot study. Pediatrics 2003; 112: 907–913.

7. Jarreau PH, Louis B, Desfrere L et al. Detection of positional airway obstruction in neonates by acoustic

reflection. American Journal of Respiratory and Critical Care Medicine 2000; 161: 1754–1756.

8. Patel R, Lenczyk M, Hannallah RS & McGill WA. Age and the onset of desaturation in apnoeic children.

Canadian Journal of Anaesthesia 1994; 41: 771–774.

9. Rendell-Baker L. History and evolution of pediatric anesthesia equipment. International Anesthesiology

Clinics 1992; 30: 1–34.

10. Erb T, Hammer J, Rutishauser M & Frei FJ. Fibre-optic bronchoscopy in sedated infants facilitated by an

airway endoscopy mask. Paediatric Anaesthesia 1999; 9: 47–52.

11. Scherhag A, Kleemann PP, Jantzen JP & Dick W. A universally applicable mask attachment for fibre-optic

intubation. The mainz universal adapter. Anaesthesist 1990; 39: 66–68.

12. Harnett M, Kinirons B, Heffernan A et al. Airway complications in infants: comparison of laryngeal mask

airway and the facemask-oral airway. Canadian Journal of Anaesthesia 2000; 47: 315–318.

13. Bordet F, Allaouchiche B, Combet S et al. Perioperative respiratory complications during general

anesthesia in pediatric patients. Anesthesiology 1999; 91: A1306 [Abstract].

14. Moylan SL & Luce MA. The reinforced laryngeal mask airway in pediatric radiotherapy. British Journal of

Anaesthesia 1993; 71: 172 [Letter/Data].

15. Morris P. Complications following the use of the laryngeal mask airway in children. Paediatric Anaesthesia

1993; 3: 297–300.

16. Braun U & Fritz U. The laryngeal mask in pediatric anaesthesia. Anaesthesiologie, Intensivmedizin,

Notfallmedizin, Schmerztherapie 1994; 29: 286–288.

17. Verghese C & Brimacombe J. Survey of laryngeal mask airway usage in 11910 patients: safety and efficacy

for conventional and nonconventional usage. Anesthesia and Analgesia 1996; 82: 129–133.

18. Lopez-Gil M, Brimacombe J & Alvarez M. Safety and efficacy of the laryngeal mask airway. A prospective

survey of 1400 children. Anaesthesia 1996; 51: 969–972.

19. Brimacombe JR. The Laryngeal Mask Anaesthesia; Principles and Practice. 2nd edn. London: Saunders; 2005.

20. Brain AIJ. The laryngeal mask; a new concept of airway management. British Journal of Anaesthesia 1983; 55:

801–805.

21. Goudsouzian NG, Denmann W, Cleveland R & Shorten G. Radiologic localization of the laryngeal mask

airway in children. Anesthesiology 1992; 77: 1085–1089.

*

*


22. Silker D & Flamm S. Fishing for a pediatric airway during remote anesthesia. Anesthesiology 2000; 93:

A1217 [Abstract].

23. Ball AJ. Laryngeal mask misplacement; a nonproblem. Anesthesia and Analgesia 1995; 81: 204 [Letter/case

report].

24. Molloy AR. Unexpected position of the laryngeal mask airway. Anaesthesia 1991; 46: 592 [Letter/case

report].

25. Splinter WM & Reid CW. Removal of the laryngeal mask airway in children: deep anaesthesia versus

awake. Journal of Clinical Anaesthesia 1997; 9: 4–7.

26. Samarkandi AH. Awake removal of the laryngeal mask airway is safe in pediatric patients. Canadian

Journal of Anaesthesia 1998; 45: 150–152.

27. Laffon M, Plaud B, Dubousset AM et al. Removal of laryngeal mask airway: airway complications in

children, anaesthetized versus awake. Paediatric Anaesthesia 1994; 4: 35–37.

28. Kitching AJ, Walpole AR & Blogg CE. Removal of the laryngeal mask airway in children: anaesthetized

compared with awake. British Journal of Anaesthesia 1996; 76: 874–876.

29. Varughesa A, Mc Cullogh D, Lewis M & Stokes M. Removal of the laryngeal mask airway (LMA) in children:

awake or deep?. Anesthesiology 1994; 81: A1321 [Abstract].

30. Pappas AL, Aribindi S, Sukhani R et al. Airway hyperreactivity with laryngeal mask airway (LMA) removal:

relationship to anesthetic depth choice. Anesthesiology 1999; 91: A1307 [Abstract].

31. Gronert BJ & Motoyama EK. Induction of anesthesia and endotracheal intubation. In Motoyama EK &

Davis PJ (eds.) Smith’s Anesthesia for Infants and Children, 6th edn. St Louis, Baltimore: Mosby, 1996, pp.

281–312.

32. Steven JM, Cohen DE & Sclabassi RJ. Anesthesia equipment and monitoring. In Motoyama EK & Davis PJ

(eds.) Smith’s Anesthesia for Infants and Children, 6th edn. St Louis, Baltimore: Mosby, 1996, pp. 229–279.

33. Cote CJ. Pediatric equipment. In Cote CJ, Todres ID, Ryan JF & Goudsouzian NG (eds.) A Practice of

Anesthesia for Infants and Children, 3rd edn. Philadelphia, London: WB Saunders, 2001, pp. 715–742.

34. Bryson GL, Chung F, Cox RG et al. Canadian ambulatory anesthesia research education group. Patient

selection in ambulatory anesthesia – an evidence-based review: part II. Canadian Journal of Anaesthesia

2004; 51: 782–794.

35. Brambrink AM & Meyer RR. Management of the pediatric airway: new developments. Current Opinion in

Anaesthesiology 2002; 15: 329–337.

36. Tait AR, Malviya S, Voepel-Lewis T et al. Risk factors for perioperative adverse respiratory events in

children with upper respiratory tract infections. Anesthesiology 2001; 95: 299–306.

37. Parnis SJ, Barker DS & Van Der Walt JH. Clinical predictors of anaesthetic complications in children with

respiratory tract infections. Paediatric Anaesthesia 2001; 11: 29–40.

38. Tait AR, Pandit UA, Voepel-Lewis T et al. Use of the laryngeal mask airway in children with upper

respiratory tract infections: a comparison with endotracheal intubation. Anesthesia and Analgesia 1998;

86: 706–711 [Abstract].

39. Schreiner MS, O’Hara I, Markakis DA & Politis GD. Do children who experience laryngospasm have an

increased risk of upper respiratory tract infection? Anesthesiology 1996; 85: 475–480.

40. Tait AR, Reynolds PI & Gutstein HB. Factors that influence an anesthesiologist’s decision to cancel elective

surgery for the child with an upper respiratory tract infection. Journal of Clinical Anesthesia 1995; 7: 491–

499.

41. Levy L, Pandit UA, Randel GI et al. Upper respiratory tract infections and general anaesthesia in children.

Perioperative complications and oxygen saturation. Anaesthesia 1992; 47: 678–682.

42. Rolf N & Cote CJ. Frequency and severity of desaturation events during general anesthesia in children

with and without upper respiratory infections. Journal of Clinical Anesthesia 1992; 4: 200–203.

43. Cohen MM & Cameron CB. Should you cancel the operation when a child has an upper respiratory tract

infection?. Anesthesia and Analgesia 1991; 72: 282–288 [Abstract].

44. DeSoto H, Patel RI, Soliman IE & Hannallah RS. Changes in oxygen saturation following general anesthesia

in children with upper respiratory infection signs and symptoms undergoing otolaryngological

procedures. Anesthesiology 1988; 68: 276–279 [Medline].

45. Tait AR & Knight PR. The effects of general anesthesia on upper respiratory tract infections in children.

Anesthesiology 1987; 67: 930–935.

46. Tartari S, Fratantonio R, Bomben R et al. Laryngeal mask vs tracheal tube in pediatric anesthesia in the

presence of upper respiratory tract infection. Minerva Anesthesiologica 2000; 66: 439–443.

*

*

*

*

*


47. Cole F. Pediatric formulae for the anesthesiologist. American Journal of Diseases of Children 1957; 94: 672–

673.

48. King BR, Baker MD, Braitman LE et al. Endotracheal tube selection in children: a comparison of four

methods. Annals of Emergency Medicine 1993; 22: 530–534.

49. Khine HH, Corddry DH, Kettrick RG et al. Comparison of cuffed and uncuffed endotracheal tubes in

young children during general anesthesia. Anesthesiology 1997; 86: 627–631.

50. Mostafa SM. Variation in subglottic size in children. Proceedings of the Royal Society of Medicine 1976; 69:

793–795.

51. Hofer CK, Ganter M, Tucci M et al. How reliable is length-based determination of body weight and

tracheal tube size in the pediatric age group? The Broselow tape reconsidered. British Journal of Anaesthesia

2002; 88: 283–285.

52. Eck JB, De Lisle Dear G, Phillips-Bute BG & Ginsberg B. Prediction of tracheal tube size in children using

multiple variables. Paediatric Anaesthesia 2002; 12: 495–498.

53. Weiss M, Dullenkopf A, Gysin C et al. Shortcomings of cuffed paediatric tracheal tubes. British Journal of

Anaesthesia 2004; 92: 78–88.

54. Manczur T, Greenough A, Nicholson GP & Rafferty GF. Resistance of pediatric and neonatal

endotracheal tubes: influence of flow rate, size and shape. Critical Care Medicine 2000; 28: 1595–1598.

55. Stevenson GW, Tobin MJ, Horn BJ et al. The effect of circuit compliance on delivered ventilation with use

of an adult circle system for time cycled volume controlled ventilation using an infant lung model.

Paediatric Anaesthesia 1998; 8: 139–144.

56. Deakers TW, Reynolds G, Stretton M & Newth CJL. Cuffed endotracheal tubes in pediatric intensive

care. The Journal of Pediatrics 1994; 125: 57–62.

57. Newth CJ, Rachman B, Patel N & Hammer J. The use of cuffed versus uncuffed endotracheal tubes in

pediatric intensive care. The Journal of Pediatrics 2004; 144: 333–337.

58. Fine GF, Fertal K & Motoyama EK. The effectiveness of controlled ventilation using cuffed versus uncuffed

ETT in infants. Anesthesiology 2000; 93: A1251 [Abstract].

59. Brambrink AM, Meyer RR & Kretz FJ. Management of pediatric airway – anatomy, physiology and new

developments in clinical practice. Anaesthesiologie und Reanimation 2003; 28: 144–151.

60. Orliaguet GA, Renaud E, Lejay M et al. Postal survey of cuffed or uncuffed tracheal tubes used for

pediatric tracheal intubation. Paediatric Anaesthesia 2001; 11: 277–281.

61. Priebe H. N2O and endotracheal cuff pressure. Anesthesia and Analgesia 2000; 90: 230–231.

62. Khalil SN, Mankarious R, Campos C et al. Absence or presence of leak around tracheal tube may not

affect postoperative croup in children. Paediatric Anaesthesia 1998; 8: 393–396.

63. Dullenkopf A, Gerber AC & Weiss M. Fit and seal characteristics of a new paediatric tracheal tube with

high volume-low pressure polyurethane cuff. Acta Anaesthesiologica Scandinavica 2005; 49: 232–237.

64. Simon L, Boucebci KJ, Orliaguet G et al. A survey of practice of tracheal intubation without muscle

relaxant in paediatric patients. Paediatric Anaesthesia 2002; 12: 36–42.

65. Brambrink AM & Koerner IP. Prehospital advanced trauma life support: how should we manage the

airway, and who should do it?. Critical Care 2004; 8: 3–5.

66. Suominen P, Baillie C, Kivioja A et al. Intubation and survival in severe paediatric blunt head trauma.

European Journal of Emergency Medicine 2000; 7: 3–7.

67. Gausche M, Lewis R, Stratton SJ et al. Effect of out-of-hospital pediatric endotracheal intubation on

survival and neurologic outcome. JAMA 2000; 283: 783–790.

68. Easley RB, Segeleon JE, Haun SE & Tobias JD. Prospective study of airway management of children

requiring endotracheal intubation before admission to a pediatric intensive care unit. Critical Care Medicine

2000; 28: 2058–2063.

69. Gerlach K, Wenzel V, von Knobelsdorff G et al. A new universal laryngoscope blade: a preliminary

comparison with Macintosh laryngoscope blades. Resuscitation 2003; 57: 63–67.

70. Henderson JJ. The use of paraglossal straight blade laryngoscopy in difficult tracheal intubation.

Anaesthesia 1997; 52: 552–560.

71. McCoy EP & Mirakhur RK. The levering laryngoscope. Anaesthesia 1993; 48: 516–519.

72. Boland LM & Casselbrant M. The Bullard laryngoscope: a new indirect oral laryngoscope (pediatric

version). Anesthesia and Analgesia 1990; 70: 105–108.

73. Brambrink AM. Fiberendoskope fur die Neonatologie. In Dorges V & Paschen H-R (eds.) Der schwierige

Atemweg — Sicherung und Management, 1st edn. Berlin: Springer, 2004.

*


74. Tsui BC & Cunningham K. Fiberoptic endotracheal intubation after topicalization with in-circuit nebulized

lidocaine in a child with a difficult airway. Anesthesia and Analgesia 2004; 98: 1286–1288.

75. Brooks P, Ree R, Rosen D & Ansermino M. Canadian pediatric anesthesiologists prefer inhalational

anesthesia to manage difficult airways. Canadian Journal of Anaesthesia 2005; 52: 285–290.

76. Johr M & Berger TM. Fibre-optic intubation through the laryngeal mask airway (LMA) as a standardized

procedure. Paediatric Anaesthesia 2004; 14: 614.

77. Muraika L, Heyman JS & Shevchenko Y. Fiberoptic tracheal intubation through a laryngeal mask airway in a

child with Treacher Collins syndrome. Anesthesia and Analgesia 2003; 97: 1298–1299.

78. Osborn IP & Soper R. It’s a disposable LMA, just cut it shorter – for fibre-optic intubation. Anesthesia and

Analgesia 2003; 97: 299–300.

79. Nussbaum E & Zagnoev M. Pediatric fibre-optic bronchoscopy with a laryngeal mask airway. Chest 2001;

120: 614–616.

80. Park WK, Kim SH & Choi H. The two different-sized fibreoptic broncoscope method in the management

of a difficult paediatric airway. Anaesthesia 2001; 56: 90–91.

81. Kleemann P, Jantzen JAH & Bonfils P. The ultra-thin bronchoscope in management of the difficult

pediatric airway. Canadian Journal of Anaesthesia 1987; 34: 606–608.

82. Rudolph C & Schlender M. Clinical experiences with fibre optic intubation with the Bonfils intubation

fibrescope. Anaesthesiologie und Reanimation 1996; 21: 127–130.

83. Shukry M, Hanson RD, Koveleskie JR & Ramadhyani U. Management of the difficult pediatric airway with

Shikani Optical Stylet. Paediatric Anaesthesia 2005; 15: 342–345.

84. Smith CE, Sidhu TS, Lever J & Pinchak AB. The complexity of tracheal intubation using rigid fiberoptic

laryngoscopy (WuScope). Anesthesia and Analgesia 1999; 89: 236–239.

85. Chhibber AK & Jaranowski K. Experience of the video intubation system in children at University of Rochester

Medical Center, Rochester, New York. The Video Intubation System in the Difficult Airway Management of Adults

and Pediatrics; A Preliminary Multi-institutional Report. Tuttlingen. Germany: Endo-Press; 2000. pp. 52–54.

86. Kaplan MB, Ward D, Chhibber A et al. The Role of the Universal Video Intubation System in the Management of

the Difficult Airway. Tuttlingen, Germany: Endo-Press; 2000.

87. Kurz S, Meyer R, Bunke K et al. Klinische Evaluation eines fiberoptischen Fuhrungsstabes mit integrierter

Videokamera zur Unterstutzung der endotrachealen Intubation bei Fruh- und Neugeborenen sowie

Sauglingen. Abstractband—Deutscher Anasthesiecongress PO 3-4.1; 2005.

88. Ganta R, Henthorn RW, Abeyewardene L et al. Comparison of fiberoptic view of the larynx on a video

camera to direct laryngoscopic view during intubation. Anesthesia and Analgesia 1996; 82: S124.

89. Mazzei WJ & Davidson TM. Comparison of laryngeal view during normal and endoscopic laryngoscopy.

Anesthesia and Analgesia 1997; 84: S252.

90. Wheeler M, Roth AG, Dsida RM et al. Teaching residents pediatric fiberoptic intubation of the trachea:

traditional fibrescope with an eyepiece versus a video-assisted technique using a fibrescope with an

integrated camera. Anesthesiology 2004; 101: 842–846.

91. Schwarz U & Weiss M. Tracheal intubation in patients with Pierre Robin sequence. Successful use of a

video intubation laryngoscope. Anaesthesist 2001; 50: 119–121.

92. Blanco G, Melman E, Cuairan V et al. Fibreoptic nasal intubation in children with anticipated and

unanticipated difficult intubation. Paediatric Anaesthesia 2001; 11: 49–53.

93. Chhibber A. Part II. The flexible video intubating scope. In Kaplan MB, Ward D & Chhibber A et al (eds.)

The Role of the Universal Video Intubation System in the Management of the Difficult Airway. Tuttlingen,

Germany: Endo-Press, 2000, pp. 13–15.

94. Groeper K, Johnson JO, Braddock SR & Tobias JD. Anaesthetic implications of Nager syndrome. Paediatric

Anaesthesia 2002; 12: 365–368.

95. Klein C. Schrittweise Kallusdistraction nach Ilizarow. Dt Arztebl 1996; 93: A3110–A3116.

96. Baines D & Kenally J. Anaesthetic implications of the mucopolysaccharidoses: a fifteen-year experience in

a children’s hospital. Anaesthesia and Intensive Care 1983; 11: 198–202.

97. Wilder RT & Kumar GB. Fiberoptic intubation complicated by pulmonary edema in a 12-year old child

with Hurler syndrome. Anesthesiology 1990; 72: 205–207.

98. Marck KW. Noma; The Face of Poverty. Medizin-Information-Therapie. Germany: MIT-Verlag; 2003.

99. Golisch W, Honig JF, Lange H & Braun U. Schwierige Intubationen bei Gesichtsfehlbildungen im

Kindesalter. Anaesthesist 1994; 43: 753–755.

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