fibreoptic nasal intubation in children with anticipated and unanticipated difficult intubation
TRANSCRIPT
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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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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Accepted 22 June 2000
FIBREOPTIC INTUBATION IN CHILDREN WITH DIFFICULT AIRWAY 53
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