Fibreoptic nasal intubation in childrenwith anticipated and unanticipated dif®cultintubation

GERARDO BLANCO, ESTELA MELMAN,

VICENTE CUAIRAN, DIANA MOYAO AND

FERNANDO ORTIZ-MONASTERIO

Departments of Thoracic Surgery and Endoscopy, Anesthesia and Respiratory Therapy, Oral andMaxillofacial Surgery and Plastic Surgery, Hospital Infantil de MeÂxico `Dr Federico GoÂmez' andHospital Angeles del Pedregal, Mexico City, Mexico

SummaryThe establishment of a tracheal airway with direct laryngoscopy can

be either a very dif®cult or an impossible task in children with

congenital or acquired facial malformations. Out of 46 patients

categorized as dif®cult tracheal intubation, ®breoptic laryngoscopy

was used successfully in 44 children anaesthetized by mask with

sevo¯urane and oxygen or by an intravenous infusion of propofol and

mask oxygenation. There were two failures (4.3%). One was due to

excessive bleeding and secretions produced by the multiple attempts

to intubate with direct laryngoscopy and the other failure in a patient

with Pierre Robin syndrome and very small nasal passages that

precluded the introduction of the endoscope. Fibreoptic laryngoscopy

was successful in 37 cases (80.4%) on the ®rst attempt to intubate and

in seven (15.2%) on a second or third attempt. We conclude that

®breoptic laryngoscopy in anaesthetized children with dif®cult

anticipated or unanticipated tracheal intubation in trained hands is a

safe technique that can be lifesaving. Therefore, we urge all anaes-

thesia trainees to become pro®cient in ®breoptic tracheal intubation.

Keywords: ®breoptic laryngoscopy; children

Introduction

The American Society of Anesthesiologists Task

Force (1) de®ned dif®cult tracheal intubation (DTI)

as an event that occurs when a `¼ proper insertion

of the tracheal tube with conventional laryngoscopy

requires more than three attempts or more than

10 min'. However, more recently, the Canadian

Airway Focus Group (CAFG) (2) offers a broader

de®nition, rede®ning DTI as `¼ when an experi-

enced laryngoscopist, using direct laryngoscopy,

requires either: 1) more than two attempts with the

same blade, or 2) a change in a blade or an adjunct to

a direct laryngoscope (i.e. bougie), or 3) use of an

alternative device or technique following failed

intubation with direct laryngoscopy'.

Establishing a tracheal airway can prove very

dif®cult in congenital or acquired malformationsCorrespondence to: Dr E. Melman, Bosque de Alerces #125, Bosquesde las, Lomas, 11700 MeÂxico, D.F., MeÂxico.

Paediatric Anaesthesia 2001 11: 49±53

Ó 2001 Blackwell Science Ltd 49

involving the upper airway. In a review of 18 500

adult cases of airway intubation, the ¯exible ®bre-

optic endoscope (FFE) was the most commonly

utilized alternative device to the direct laryngo-

scope, either electively or in the event of an unan-

ticipated dif®cult intubation (3).

In this paper, we report on our experience with

nasal ®breoptic laryngoscopy (NFI) using the ¯ex-

ible ®breoptic endoscope in 46 children assessed as

DTI due to congenital or acquired malformations.

Methods

Forty-six patients were assessed preoperatively us-

ing standard predictors of dif®cult airway intuba-

tion (3) such as: (i) Mallampati's score (M), Table 1

(4), (ii) thyromental distance in adolescents, (iii)

mouth opening of less than 4 cm, and (iv) Cormack

and Lehane's Classi®cation of Laryngeal View (C±

L), Table 2 (5). All patients required anaesthesia

with tracheal intubation for surgical correction of

the congenital or acquired pathology that created

the dif®cult airway.

After careful preoperative evaluation, nasal ®bre-

optic endoscopy was recommended as the proce-

dure of choice for intubation in 38 cases of

anticipated dif®cult intubation due either to the

underlying pathology, a Mallampati class III score,

or a mouth opening of less than 40 mm. In eight

cases of unanticipated DTI, graded either as Mal-

lampati class II or having a borderline (up to 40 mm)

mouth opening or a normal opening, a direct

laryngoscopy was attempted. However, after several

failed trials to intubate, NFI was undertaken (Cor-

mack±Lehane grades III±IV).

Nasal ®breoptic intubation was performed using

two different endoscopes, the 3.3 mm Pentax naso-

pharyngolaryngoscope in infants, or the Olympus

4.5 mm bronchoscope in older children.

All patients were monitored using noninvasive

blood pressure, pulse oximetry, electrocardiogram,

and temperature; capnography was added after

intubation was accomplished. An intravenous (i.v.)

solution with lactated Ringer's was initiated and

0.01 mgákg±1 of atropine was administered i.v.

before commencing, followed by nasal application

of 0.25% oxymethazoline nasal drops and a spray of

4% lidocaine applied to the pharynx through a nasal

catheter; the endoscope and tracheal tube were also

sprayed with lidocaine to facilitate threading of the

tube. Anaesthesia was initiated with a face mask

using halothane or sevo¯urane and oxygen or an i.v.

infusion of propofol with oxygen by mask, always

maintaining spontaneous ventilation. The FFE was

inserted within the tracheal tube and placed blindly

into the nasopharynx. After the glottis and vocal

cords were visualized, the tube was threaded with-

out dif®culty through the cords into the trachea and

held at the carina to avoid displacement of the tube

as withdrawal of the endoscope was carried out (6).

In instances where intubation failed at the ®rst

attempt, the tube and endoscope were immediately

removed, the patient was oxygenated, anaesthesia

was deepened with halothane or i.v. propofol, and

thereafter the endoscopic procedure was reinitiated,

squirting 1±2 ml of 1% lidocaine through the suction

port of the endoscope to provide a quiet ®eld.

Results

Table 3 lists the underlying pathology and Table 4,

the age, sex, underlying pathology, size of tracheal

tube inserted, mouth opening (mm), Mallampati and

Cormack±Lehane's classi®cation, as well as the

thyromental distance when it measured less than

6.0 cm in length. Endoscopically guided intubation

was successful in 37 cases at the ®rst attempt

(80.4%), with another seven cases (15.2%) requiring

two or three attempts each (Table 4). One of these

cases was that of a child with burn sequelae (case

33), in which the epiglottis adhering to the pharynx

Table 1Mallampati's score

Class I Faucial pillars, soft palate and uvula could be visualizedClass II Faucial pillars and soft palate could be visualized, but

uvula was masked by the base of the tongueClass III Only soft palate could be visualized

Table 2Cormack±Lehane's classi®cation

Grade 1 Glottis exposed (no dif®culty to intubation)Grade 2 Only posterior commissure of glottis can be exposed

(mild to moderate dif®culty)Grade 3 No exposure of the glottis (severe dif®culty)Grade 4 No exposure of the glottis, nor of the corniculate

cartilages (intubation impossible, execept for specialmethods)

50 G. BLANCO ET AL .

Ó 2001 Blackwell Science Ltd, Paediatric Anaesthesia, 11, 49±53

required the use of the Laser to cut the ®brous bands

before the endoscope could be introduced.

In two cases (4.3%), ®breoptic intubation was not

possible. One case was due to excessive bleeding

and secretions produced by the multiple attempts to

intubate with direct laryngoscopy (case 6). The

second case was that of an ex-premie, a 2-month-

old 2.2 kg baby with Pierre Robin syndrome, scored

as Mallampati II and after a preoperative laryngos-

copy, as C±L III, who was scheduled for bilateral

mandibular distraction under general anaesthesia

with NFI. In this patient, small nasal passages and a

very large tongue impeded visualization of the

airway with the endoscope. The patient was suc-

cessfully intubated after several attempts with direct

laryngoscopy (C±L III) after pulling and holding the

tongue outside othe mouth with forceps and apply-

ing pressure on the larynx by an assistant (case 31).

No other complications occurred except for mild

to moderate nasal bleeding in ®ve cases (Table 4).

Coughing after intubation was sporadic and was

immediately arrested by deepening anaesthesia or

by administration of a muscle relaxant.

Discussion

Dif®cult tracheal intubation is a frequent challenge

to anaesthesiologists and endoscopists. In 1967,

Murphy used for the ®rst time a ®breoptic endo-

scope for nasal intubation in a patient with Still's

syndrome (juvenile rheumatoid arthritis) (7). Subse-

quently, the procedure began gaining popularity as

a learning curve was developed.

Various anatomical and pathological abnormalit-

ies may lead to dif®cult airways. Among our

patients, hemifacial microsomy (HFM) was the most

frequent congenital pathology with secondary uni-

lateral or bilateral temporomandibular ankylosis

(TMA). TMA secondary to trauma or to infectious

processes of the mouth were the two most common

causes of acquired pathology.

Mandibular hypoplasia in different proportions

occurs as part of syndromes such as Pierre Robin,

Goldenhar, Nager, Treacher-Collins, or HFM. The

latter is the second most common facial congenital

malformation after cleft lip and palate, the hypo-

plastic mandible being the conspicuous deformity.

This can be present either unilaterally or bilater-

ally, is accompanied by mandibular deviation

evident at the chin (which is deviated to the

affected side), shortening of the muscles of masti-

cation and of the ramus, and is often associated

with condyle malformation or its complete ab-

sence, and microtia and hypoplasia of the soft

tissues of the cheek, making evident the notorious

facial asymmetry (8).

Recently, Nargozian reported dif®cult intubation

in 21% of patients with unilateral HFM and very

dif®cult in 9% of a total of 82 cases, whereas in

bilateral HFM (n � 20), intubation was dif®cult in

35% and very dif®cult to intubate in another 35% of

these cases, suggesting that although direct laryn-

goscopy may be a reasonable approach in this subset

of patients, the possible need for an intubation

technique other than rigid direct laryngoscopy may

be considered regardless of the anatomical classi®-

cation of the mandible (9).

In 1988, we initiated ®breoptic endoscopy at our

Institution as part of management in cases of

anticipated dif®culty in direct laryngoscopy, or for

cases in which direct intubation proved impossible,

developing a learning curve for this procedure in

collaboration with the Department of Thoracic Sur-

gery and Endoscopy.

Most of our cases have been children, with only a

few of these being infants. Among the latter, an

interesting case was that of an infant who had

undergone oesophageal interposition with the colon

requiring frequent aspiration of bronchial secretions.

Use of ®bereoptic intubation to avoid extension of

the neck with consequent rupture of the anastomotic

line of sutures proved an excellent indication. The

use of the FFE in children with severe sequelae of

facial burns or juvenile ®brosarcomas has been, in

Table 3Underlying pathology

Pathology n

TMA (congenital or acquired) 26Congenital maxillomandibular fusion 2Freeman-Sheldon 1Hunter 1Klipper-Feil 1Pierre Robin 2Treacher Collins 5Juvenile ®brosarcoma of the oral cavity 1Burn sequelae 6Colon interposition 1

Total 46

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Ó 2001 Blackwell Science Ltd, Paediatric Anaesthesia, 11, 49±53

Table 4Patient data

n Diagnosis Sex

Age(years,months) Tube size

Mouthopening

M = I, II, IIIC±L = I, II, III, IVD = < 6 cm Observations

1 Pierre Robin F 5 5/12 5.5 15 mm M±III Marked mandibular hypoplasia2 TMA (right) F 11 6.0 w/c Normal M±II HFM, laryngoscopy3 TMA (left) F 5 10/12 5.5 35 mm M±II Neuro®bromatosis, HFM

laryngoscopy4 TMA (right) M 6 11/12 5.0 10 mm M±III Secondary to infection5 TMA bilateral M 7 5.5 Borderline M±II Traumatic laryngoscopy6 TMA (left) M 9 5.0 Normal M±II, C±L III HFM, bleeding, failed NFI. Blind

intubation7 Juvenile ®brosarcoma M 9 5.5 Normal M±III Oral cavity8 TMA bilateral M 8 5/12 5.5 10 mm M±III HFM9 TMA (right) M 8 8/12 4.5 10 mm M±III Secondary to trauma

10 TMA bilateral M 14 6.0 10 mm M±III Secondary to trauma11 TMA (right) M 3 2/12 4.5 5 mm M±III Secondary to infection12 Maxillo-mandibular fusion M 5/12 4.0 3 mm Congenital13 TMA (left) F 5 7/12 4.5 5 mm M±III Secondary to trauma14 Microstomy (burn sequelae) M 1 1/12 4.0 10 mm M±III Ingestion of caustics15 TMA bilateral F 3 4/12 5.0 5 mm M±III HFM16 TMA (right) F 10 5.0 3 mm M±III Secondary to infection17 Maxillomandibular fusion M 10/12 4.0 0 Congenital18 TMA bilateral M 2 6/12 4.5 5 mm M±III Secondary to trauma19 TMA (right) M 9 5.5 10 mm M±III HFM20 Treacher Collins F 8 7/12 4.5 15 mm M±III ASD21 Microstomy (burn sequelae) M 1 5/12 4.5 10 mm M±III Ingestion of caustics22 Hunter F 11 5/12 5.0 Normal M±III Very short neck, macroglosia23 Treacher Collins M 8 5.0 Normal M±II Laryngoscopy24 Colon interposition M 4 5.0 Normal Inability to extend neck25 TMA bilateral F 8 5.5 w/c 5 mm M±III HFM26 Klippel-Feil F 5 5.0 Normal Multiple malformations27 Freeman Sheldon M 2 7/12 5.0 Borderline M±III Micrognathia28 TMA (right) F 10 6.0 25 mm M±III HFM29 Burn sequelae M 14 11/12 6.5 40 mm D < 6 Laryngoscopy30 TMA bilateral F 17 6.5 15 mm M±III, D < 6 HFM31 Pierre Robin M 2/12 3.0 Normal M±II, C±L III Failed NFI32 TMA (left) M 8 5.5 w/c 12 mm M±III HFM, second attempt33 Burn sequelae F 5 5.5 Normal M±I, C±L IV Laryngoscopy, NFI second

attempt34 Treacher Collins F 5 5.5 30 mm M±III Bleeding, third attempt, NFI35 Treacher Collins M 11 5.0 w/c Normal M±II, C±L III Laryngoscopy, second attempt,

bleeding36 Treacher Collins F 4 5.5 30 mm M±III Narrow airway37 TMA (right) F 3 5/12 4.5 10 mm M±III HFM38 TMA (right) F 7 4.5 20 mm M±III HFM, second attempt NFI,

bleeding39 TMA bilateral F 13 5.5 30 mm M±III HFM40 TMA bilateral F 7 5.5 15 mm M±III, C±L IV HFM, bleeding41 TMA bilateral F 5 5.0 15 mm M±III HFM42 TMA bilateral M 15 5.5 30 mm M±II±III HFM, laryngoscopy second

attempt43 TMA (right) F 4 5.0 8 mm M±III HFM44 TMA bilateral F 10 6.0 w/c Normal M±II, C±L IV HFM, laryngoscopy45 Burn sequelae M 13 6.5 w/c 0 D < 6 Face and neck46 Burn sequelae M 12 6/12 6.5 w/c 0 D < 6 Face, neck and upper thorax

Mallampati, M; Cormack±Lehane, C±L; D, thyromental distance (cm); w/c, with cuff; TMA, temporomandibular ankylosis; HFM,hemifacial microsomia; ASD, atrial septal defect; NFI, nasal ®breoptic intubation.

52 G. BLANCO ET AL .

Ó 2001 Blackwell Science Ltd, Paediatric Anaesthesia, 11, 49±53

our experience, another excellent indication

(Tables 3 and 4).

One of the problems that can be encountered

during ®breoptic intubation is that the tip of the

tracheal tube can accidentally be introduced into the

laryngeal ventricle (between the ventricular and

vocal folds); in these cases, a simple manoeuvre that

consists of rotating and pushing the tube will allow

it to slide over the posterior commissure of the

glottis and enter the larynx. Another problem can be

the trauma to the nasal mucosa caused by the

passage of the tube and endoscope; this occurred in

®ve cases, was mild to moderate, but did not impede

visualization with the endoscope. The use of

armoured tracheal tubes with a more rounded and

more ¯exible tip has also facilitated ®breoptic

intubation.

In one case, ®beroptic intubation was unsuccessful

due to excessive bleeding and secretions; this

occurred after several attempts to intubate with

direct laryngoscopy.

Regardless of the level of clinical experience and

expertise, most anaesthesiologists would agree that

management of a patient with a dif®cult airway is

perhaps the most challenging task in anaesthesia.

Inability to provide ventilation and perform tracheal

intubation is associated with major complications

and even death (10). Direct laryngoscopy in dif®cult

situations remains our ®rst choice; however, when

faced with dif®cult visualization of the laryngeal

structures, an alternative approach to achieve suc-

cessful placement of a tracheal tube without undue

patient trauma should be sought.

It is claimed that tracheal intubation with ®bre-

optic endoscopy is a technique particularly well

suited for patients who are awake because the use of

this instrument may be rendered more dif®cult

during general anaesthesia due to loss of tone in

the muscles that support the tongue and, indirectly,

the epiglottis (2). In infants and children, collapse of

these structures under general anaesthesia does not

represent a major burden during the procedure, due

perhaps to the better tone of these structures in the

early years of life. However, loss of patency of the

child's airway can occur rapidly with hypoxaemia

and desaturation due to high baseline oxygen

consumption. Therefore, during airway manipula-

tion, administration of oxygen as well as of atropine

to prevent bradycardia and to dry secretions are

essential steps to ensure the success of this technique

in infants and children.

Finally, as competence and familiarity with the

use of this instrument have been acquired, we have

also observed the importance of having all our

trainees learn to use this important tool as part of the

teaching programme (11).

References

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2 Crosby ET, Cooper RM, Douglas MJ et al. The unanticipateddif®cult airway with recommendations for management. Can JAnaesth 1998; 45: 757±776.

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4 Mallampati SR, Gatt SP, Gugino LD et al. A clinical sign topredict dif®cult tracheal intubation: a prospective study.Can Anaesth Soc J 1985; 32: 429±434.

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8 Converse JM, McCarthy JG, Coccaro PJ et al. Clinical aspects ofcraniofacial microsomia. In: Converse JM, McCarthy JG,Wood-Smith D, eds. Symposium on Diagnosis and Treatment ofCraniofacial Anomalies, vol 20. St Louis, MO: CV Mosby, 1979:461±475.

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Accepted 22 June 2000

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Ó 2001 Blackwell Science Ltd, Paediatric Anaesthesia, 11, 49±53