Rigid nasendoscope with video camera system for intubation in infants with Pierre-Robin sequence

Ravishankar et al.

anaesthetized, we were able to proceed calmly with the task of tracheal intubation. We were prepared for laryngospasm, coughing, or breath holding. If laryngospasm is encountered during the insertion of the LMA, we would recommend the use of succinylcholine and subsequent ventilation through the LMA, striving for an adequate depth of anaesthesia. As LMA failure to ventilate children with abnormal airway anatomy has also been reported, equipment to deal with dif®cult intubation and emergency tracheostomy should be available.17±19

Conclusions The use of sedation and topical anaesthesia of the pharynx and larynx allowed placement of the LMA to secure safely the airway in a paediatric patient with severe facial abnormalities on two separate occasions. The LMA was used as a conduit to facilitate inhalation induction of general anaesthesia in a patient in whom the use of facemask was not desirable.

References 1 Tessier P. Anatomical classi®cation of facial, craniofacial and laterofacial clefts. In: McCarthy JG ed. Plastic Surgery Vol. 4. Philadelphia: W. B. Saunders, 1999; 2922±73 2 Darzi MA, Chowdri NA. Oblique facial clefts: a report of Tessier numbers 3, 4, 5 and 9 clefts. Cleft Palate Craniofacial J 1993; 30: 414±5 3 Longaker MT, Lipshuts GS, Kawamoto HK jr. Reconstruction of Tessier no. 4 clefts revisited. Plast Reconstr Surg 1997; 99: 1501±7 4 Hatch DJ. Airway management in cleft lip and palate surgery. Br J Anaesth 1996; 76: 755±6 5 Berry AM, Brimacombe JR, Verghese C. The laryngeal mask airway in emergency medicine, neonatal resuscitation, and intensive care medicine. Int Anesthesiol Clin 1998; 36: 91±109

6 Boehringer LA, Bennie RE. Laringeal mask airway and the paediatric patient. Int Anesthesiol Clin 1998; 36: 45±60 7 Lopez-Gil M, Brimacombe J, Alvarez M. Safety and ef®cacy of the laryngeal mask airway. A prospective survey of 1400 children. Anaesthesia 1996; 51: 969±72 8 Brain AIJ, McGhee TD, McAteer EJ, Thomas A, Abu-Saad MAW, Bushman JA. The laryngeal mask airway. Development and preliminary trial of a new type of airway. Anaesthesia 1985; 40: 356±61 9 Johnston DF, Wrighley SR, Robb PJ, Jones HE. The laryngeal mask airway in paediatric anaesthesia. Anaesthesia 1990; 45: 924±7 10 White AP, Billingham IM. Laryngeal mask guided intubation in paediatric anaesthesia. Paediat Anaesth 1992; 2: 265 11 Goldie AS, Hudson I. Fibreoptic tracheal intubation through a modi®ed laryngeal mask. Paediat Anaesth 1992; 2: 343±4 12 Walker RWM. The laryngeal mask airway in the dif®cult paediatric airway: an assessment of positioning and use in ®breoptic intubation. Paediat Anaesth 2000; 10: 53±8 13 Hansen TG, Joensen H, Henneberg SW, Hole P. Laryngeal mask airway guided tracheal intubation in a neonate with the Pierre Robin Syndrome. Acta Anaesthesiol Scand 1995; 39: 129±31 14 Wheatley RS, Stainthorp SF. Intubation of a one-day-old baby with the Pierre Robin Syndrome via a laryngeal mask. Anaesthesia 1994; 49: 733 15 Hatch DJ. Magill's endotracheal catheter device for use during repair of cleft lip and palate. Paediatr Anaesth 1995; 5: 199±201 16 Gunawardana RH. Dif®cult laryngoscopy in cleft lip and palate surgery. Br J Anaesth 1996; 76: 757±9 17 Brimacombe JR, Berry AM, White PF. The laryngeal mask airway: limitations and controversies. Int Anesthesiol Clin 1998; 36: 155±82 18 ElHammar F, Dubreuil M, Benoit I, et al. A dif®cult intubation of an infant with McKusick-Kaufman syndrome. Failure of the laryngeal mask-®broscope sequence. Ann Fr Anesth Reanim 1998; 17: 240±2 19 Busoni P, Fognani G. Failure of the laryngeal mask to secure the airway in a patient with Hunter's syndrome (mucopolysaccharidosis type II). Paediat Anaesth 1999; 9: 153±5

British Journal of Anaesthesia 87 (5): 728±31 (2001)

Rigid nasendoscope with video camera system for intubation in infants with Pierre-Robin sequence M. Ravishankar1, P. Kundra1*, K. Agrawal2, N. S. Kutralam1, N. Arun and O. P. Vijaykumar1 1

Department of Anaesthesiology and Critical Care and 2Department of Plastic Surgery, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry 605 006, India *Corresponding author: D-II/21, JIPMER campus, Pondicherry 605 006, India We describe an alternative intubation technique using a rigid nasendoscope and a video camera monitor system in two infants with Pierre-Robin sequence presenting for palatoplasty. After induction with an inhalational anaesthetic technique, the tracheas of the infants could not be intubated with direct laryngoscopy using a Wisconsin blade. In the absence of a ¯exible paedia-

Ó The Board of Management and Trustees of the British Journal of Anaesthesia 2002

Rigid nasendoscope with video camera system for intubation

tric ®brescope, a rigid endoscope (2.7 mm, 70° lateral illumination) was passed orally to provide a view of the glottis on the monitor screen. A tracheal tube, bent into a J-shape using a stylet, was inserted orally and manipulated into the trachea, under video guidance. This technique proved to be simple, permitting a favourable view of the glottis. It should be considered for passing a tracheal tube through the vocal cords in infants who present with a dif®cult airway. Br J Anaesth 2002; 88: 728±31. Keywords: complications, intubation tracheal; complications, Pierre-Robin sequence; equipment, rigid nasendoscope; equipment, video camera Accepted for publication: December 18, 2001

Management of the dif®cult paediatric airway, especially in infants, remains a challenge to the anaesthetist. Various techniques have been tried to secure the airway in children, but ¯exible ®bre-optic intubation remains the technique of choice. Despite extensive use, the technique has been reported to fail when most needed, namely in infants with distorted airway anatomy.1 We report the use of a rigid endoscope with a video camera system for tracheal intubation in two infants with Pierre-Robin sequence presenting for palatoplasty. Rigid nasendoscopes with 70° lateral illumination (Fig. 1) are readily available in operating rooms, being used by plastic and ENT surgeons.

Case 1 A 9-month-old infant weighing 10 kg with features of Pierre-Robin sequence presented for palatoplasty (Fig. 1). On preoperative assessment, the child had bilateral cleft lip, premaxillary prominence with an interalveolar cleft of 1.8 cm and micrognathia with a maxillary overreach of 1.1 cm. The intertragal distance through the maxilla and mandible was 18 and 16 cm respectively. Dif®cult intubation was anticipated and equipment pertaining to emergency jet ventilation was kept ready in case of failure. In the absence of a paediatric ¯exible ®brescope, the plan was to perform conventional direct laryngoscopy with a Wisconsin straight blade, using an inhalational anaesthetic technique. Alternatively, an attempt at tracheal intubation would be made using the rigid endoscope and a video camera monitor system. The child was starved for 4 h. Promethazine syrup 10 mg and i.m. atropine 0.2 mg were administered 60 min before surgery. On arrival in the operating room, monitoring of electrocardiogram and non-invasive blood pressure (Minimon-7133; Larson & Toubro Medical, India; under licence from Kontron Instruments, S.P.A., Italy) and pulse oximetry (RGM-5250; Ohmeda; Louisville, CO 800279650, USA) were commenced. Induction of anaesthesia was initiated with halothane in oxygen through an Ayre T-piece with Jackson-Rees' modi®cation. It was possible to maintain airway patency with head extension and upward jaw thrust, and positive pressure of the lungs could be

Fig 1 (A) A 9-month-old child with bilateral cleft lip, cleft palate, micrognathia and glossoptosis (case 1) for palatoplasty. (B) Equipment used to aid tracheal intubation under video guidance. 70° angle viewing rigid nasendoscope connected to the light source and the camera with a universal adapter.

maintained with the facemask. After a satisfactory depth of anaesthesia had been achieved, an oropharyngeal spray with 10% lidocaine 20 mg (1 puff=10 mg) was used to reduce airway reactivity during laryngeal manipulation. On direct laryngoscopy, no glottic structure could be visualized

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Fig 2 Endoscopic views with the rigid nasendoscope used for tracheal intubation. (A) View of the glottis from a distance. (B) Closer view of the glottis. (C) View of glottis and tube together. (D) Lifting the epiglottis with the tube. (E) Manipulation of the tube into glottis. (F) Final position of the tube.

(grade 4),2 and it was possible to view only the tip of the epiglottis with considerable external laryngeal pressure. After two unsuccessful attempts to intubate the trachea, the facemask was reapplied to deepen anaesthesia. It was decided not to attempt further laryngoscopy or intubation and to use an alternative technique. Once a satisfactory depth of anaesthesia had been reached, an assistant was instructed to stabilize the head and pull out the tongue with tongue-holding forceps. The anaesthetist introduced the rigid endoscope orally (2.7 mm external diameter, 70° nasal; Karl Storz-Endoskope, Tuttlingen, Germany) connected to a light source, with an endovision camera (Endo 3000; Pentax) mounted on a universal adaptor attached to the endoscope (Fig. 1). As soon as the endoscope reached the uvula, a grade 2 view2 of the glottis was displayed on the video monitor (PVM-14M4E; Sony). The endoscope was stabilized with the left hand and a 4 mm tracheal tube (RAE, Mallinckrodt Medical, Athlone, Ireand), mounted on a stylet and curved to produce a J-shape, was introduced in the midline with the right hand. Looking at the monitor continuously, the tip of the tracheal tube was brought into view and manipulated to pass through the vocal cords into the trachea (Fig. 2). The endoscope was removed and proper placement of the tracheal tube was con®rmed by ausculta-

tion and capnography. Palatoplasty was performed under halothane, nitrous oxide, oxygen and vecuronium, and recovery from anaesthesia was uneventful. Three months later, the same child was intubated using the same technique for repair of the lip and premaxilla (Fig. 2).

Case 2 An 11-month-old infant weighing 8 kg with features of Pierre-Robin sequence presented for palatoplasty. On preoperative assessment, the child had bilateral cleft lip, with mouth opening of 3 cm, micrognathia and a maxillary overreach of 1 cm. The intertragal distance through the maxilla and mandible was 18.5 and 17 cm respectively. Induction of anaesthesia was similar to that used in the previous case. A grade 3 laryngoscopic view2 of the glottis was possible only after external laryngeal pressure and an attempt to pass the tracheal tube into the trachea was unsuccessful. The facemask was applied to deepen anaesthesia. Once a satisfactory depth of anaesthesia had been reestablished, a rigid nasendoscope with the video camera system was used to view the glottis. Successful intubation was performed in 85 s. The entire intraoperative and postoperative course was uneventful.

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Discussion The 70° lateral illumination of the rigid endoscope provides an excellent view of the larynx as soon as the endoscope is passed. Its oral introduction is atraumatic and does not require additional skills for viewing the larynx. The ®eld of vision has suitable magni®cation with better resolution than the frontal/end-on vision of the ¯exible ®brescope. Introducing the tracheal tube and the endoscope separately permits the use of a tracheal tube of an appropriate size. The dynamics of tracheal tube insertion can be viewed continuously on the screen until the whole process is completed. If the tracheal tube slips or is caught at the glottis, it can be manipulated under visual control to negotiate the glottic aperture. Nevertheless, the technique requires co-ordination between the hands (one hand holds the endoscope and ®xes the view of the glottis and the other manipulates the tracheal tube), and one assistant to stabilize the head, pull out the tongue and monitor the child. The endoscopist has to focus his attention constantly on the monitor screen. It is necessary to curve the tracheal tube into a J-shape for it to be viewed with the glottis. Katz and colleagues3 used a tube-mounted 0° endoscope in adults and children with normal airways for tracheal intubation, which provides an end-on view of the glottis. In infants with a dif®cult airway, forceful lifting of the tongue with a 0° endoscope with external diameter less than 3 mm might damage the ®bre-optic bundles within the endoscope. A 70° angle, on the other hand, provides a suitable ®eld of vision `around the corner' to view the glottis from the pharynx. The tongue needs only to be lifted from the posterior pharyngeal wall (Fig. 3). In expert hands, the technique of using a ¯exible ®brescope is safe but considerable dif®culty in advancing the tracheal tube over the ®brescope occurs in 23% of cases.4 The paediatric ¯exible ®brescope, with an external diameter of 2±2.5 mm, has fewer optical ®bres, which restricts the ®eld of vision further and provides a smaller image with poor resolution.5 The technique we have described is similar in concept to the use of a rigid ®bre-optic laryngoscope, the Upsherscope, in adults.6 However, a few limitations of this equipment have been noted. The blade shape does not match the airway anatomy in all patients. The angle of blade curvature and

Fig 3 Difference in the ®eld of vision between a 0° and a 70° endoscope.

especially that of the tube channel is small (approximately 60°), often resulting in a restricted view of the larynx. Fridrich and colleagues6 recommend an angle of curvature closer to 90°, like that used in the Bullard laryngoscope or Augustine Scope. Secondly, lifting the epiglottis can be dif®cult. The entire blade tip is not seen during the intubation procedure, and thus picking up the epiglottis is a blind manoeuvre. The instrument is also expensive. We conclude that a 70° rigid nasendoscope allows tracheal intubation in infants with a dif®cult airway without traumatizing or distorting the upper airway. However, shortening the nasendoscope would improve stability.

References

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1 Audenaert SM, Montgomery CL, Stone B, Akin RE, Lock RL. Retrograde-assisted ®beroptic tracheal intubation in children with dif®cult airways. Anesth Analg 1991; 73: 660±4 2 Cormack RS, Lehane J. Dif®cult tracheal intubation in obstetrics. Anaesthesia 1984; 39: 1105±11 3 Katz RL, Berci G. The optical styletÐa new intubation technique for adults and children with speci®c reference for teaching. Anesthesiology 1979; 51: 251±4 4 Hakala P, Randell T. Comparison between two ®brescopes with different diameter insertion cords for ®breoptic intubation. Anaesthesia 1995; 50: 735±7 5 Ovassapian A. Fiberoptic Airway Endoscopy in Anesthesia and Critical Care, 1st edn. New York: Raven Press, 1990; 6±8 6 Fridrich P, Frass M, Krenn CG, Weinstabl C, Benumof JL, Krafft P. The UpsherScope in routine and dif®cult airway management. A randomised, controlled clinical trial. Anesth Analg 1997; 85: 1377±81