Abstract

We report the perioperative airway management in a 12-year-old boy suffering from Treacher Collins syndrome (TCS) and severe mental retardation who was scheduled for elective dental treatment under general anesthesia. TSC is also known as mandibulofacial dysostosis or Franceschetti syndrome, usually with a potentially difficult airway presentation. It is a major challenge for the anesthesiologist to manage an uncooperative child with such a congenital airway anomaly. A difficult airway was en countered during induction of general anesthesia, and both oral intubation by direct laryngoscopy and classic laryngeal mask airway (LMA) insertion were unsuccessful. In an expedient critical trial, with the cooperation of two anesthesiologists, one performing nasal fiberoptic intubation and the other maintaining oral mask ventilation, a nasal endotracheal tube was successfully placed at the first attempt, although at the expense of prolonged respiratory depression in the patient. Therefore, fiberoptic nasal intubation simultaneously with mask ventilation for placement of the endotracheal tube is a practical substitute for a difficult airway usually managed by LMA with inadequate ventilation. After extubation, tracheostomy may be indicated if the TCS patient suffers from persistent difficult upper airway in consequence of a traumatic intubation.

Keywords

airway obstruction; endotracheal intubation; fiberoptic technology; general anesthesia; Treacher Collins syndrome;

1. Introduction

Treacher Collins syndrome (TCS), also known as mandibulofacial dysostosis, is a congenital genetic anomaly arising from defective growth of the first branchial arch. The syndrome is associated with pharyngeal hypoplasia, upper airway obstruction and difficult intubation.¹⁻³ In Taiwan, poor dental hygiene is not uncommon in disabled and mentally retarded patients. The government has launched a public health program to encourage dentists to provide dental care to this small, disadvantaged population, and general anesthesia sometimes becomes mandatory for a pro tracted dental procedure or in an uncooperative patient. An obstructive patient with a potentially difficult airway may challenge anesthesiologists perioperatively, particularly during induction of general anesthesia and extubation.

TCS is well known to present difficulties in intubation, and many techniques aiming at successful airway management have been reported, such as intubation under fiberoptic bronchoscopy, the use of a laryngeal mask airway (LMA), fiberoptic intubation through LMA, and even tracheostomy as a last resort.¹⁻⁵ However, there are very few clinical reports concerning subsequent persistent upper air way obstruction after extubation. We herein report a 12-year-old boy suffering from TCS and severe mental retardation who was scheduled for dental treat ment. Airway management for both difficult intubation during induction of anesthesia and subsequent extubation in this case are presented and the main points discussed.

2. Case Report

A 12-year-old boy, 27 kg in weight and 140 cm in height, was diagnosed with TCS during his early childhood. He also suffered from severe mental retardation and microtia with complete hearing loss. The rea son for this admission was to undergo operative dentistry because of multiple dental caries. His past history did not reveal any operation or anesthesia. During the preanesthetic visit, we noted that his facial contours and mouth were abnormal, characterized by hypoplastic mandibles and zygomas, a small oral cavity and retracted lower jaw (Figure 1).

We abandoned a conscious intubation technique because the patient was exceedingly uncooperative and anxious. We decided to choose inhalational induction with intravenous (i.v.) sedation. No premedication was given, and unconsciousness was induced with i.v. thiopental 75 mg and ketamine 15 mg given slowly in the waiting room. Spontaneous respiration was preserved, and he was transported to the operating room without delay. Routine intraoperative monitoring included electrocardiography, pulse oximetry, automated noninvasive blood pressure and capnography.

Unfortunately, inadequate chest movement was observed while ventilating the lungs with a slow step ped increase in sevoflurane concentration in oxygen at a flow rate of 6 L/minute via a standard face mask. No improvement was noted after the insertion of a proper-sized oropharyngeal airway. Severe airway obstruction was encountered. Direct Macintosh laryn goscopy revealed a modified CormarkLehane scale (MCLS) grade 4 glottic view with backward upward and rightward pressure on the thyroid cartilage. A size 2.5 classic LMA was immediately inserted, but in vain. At this juncture, SpO₂ fell below 60% and heart rate gradually dropped to 45 beats/minute. Atro pine 0.5 mg and epinephrine 50 μg were given intravenously. Fiberoptic nasal intubation (FNI) (Olympus ENF XP 4.5 mm; Olympus, Tokyo, Japan) was contem plated to rapidly insert an endotracheal tube (ETT). While one anesthesiologist stabilized the head and maintained oral mask ventilation, the senior anes thesiologist executed FNI via the left nostril while an assistant compressed the right nostril to prevent air leakage. The patient was successfully intubated with a 5.0-mm ETT at the first attempt and the FNI procedure took less than 60 seconds. The pa tient’s vital signs became normal after restoration of normal ventilation. The operation was postponed, and the patient was transferred to the intensive care unit (ICU) for close observation, with the nasal tracheal tube remaining in place.

The patient regained spontaneous respiration the next day. His vital signs were stable apart from a mild fever. He was sedated for the following 4 days because of a lack of cooperation. Brain computed tomography follow-up revealed no specific intracranial lesion. Because of cellulitis, which developed due to severe dental caries (including the right upper lateral incisor, the right upper first premolar, the right upper second premolar, the left upper central incisor, the left upper first premolar, the left upper first molar, the right lower first molar, the left lower first molar, and the left lower first milk molar), he was scheduled for an urgent operation with the nasal tracheal tube in situ for anesthesia, and the operation was performed uneventfully.

On the second postoperative day, we planned to extubate him with the assistance of a Cook^® airway exchange catheter (CAEC; inner diameter, 1.6 mm; outer diameter, 3.0 mm; length, 45 cm; Cook, Bloomington, IN, USA) as an airway to convey oxygen and to forestall difficult reintubation in the normal manner. Unfortunately, because of intolerance to the CAEC and emergence of upper airway obstruction, he was reintubated in the ICU with the assistance of the CAEC. After three failed attempts at extubation, we decided to perform a tracheostomy to avoid prolonged intubation. The tracheostomy served its purpose and a month later, the patient was discharged with no significant problems during 18 months of follow-up.

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Figure 1 Photograph of a 12-year-old boy with Treacher Collins syndrome showing severe mandibular hypoplasia. In situ 5.0# endotracheal tube with cuff was inserted by fiberoptic technique through the nasal route.

3. Discussion

TCS, synonymous with mandibulofacial dysostosis, is a congenital disease resulting from a defect of the first branchial arch.⁶ In our case, facial bone anomalies were accompanied by a small oral cavity and small retracted lower jaw leading to difficulty in mask ventilation and direct laryngoscopy. In the literature, it was reported as a hazard for anesthesia since 1963, and has been well known to present a difficult intubation since then.^1,4,7,8

The application of a conscious intubation technique is valuable and safe in expected difficult airways. In this case, we could not perform the technique without the patient’s cooperation. In the literature, LMA is a suitable and useful airway device in pediatric difficult airway.^1,2,8−11 Unfortunately, in our case, acceptable ventilation did not materialize after the placement of a classic 2.5# LMA. Takita et al reported a case series of failure to establish a patent airway, in which two out of seven patients were involved in the use of an LMA.¹² Accordingly, it is considered that the LMA cannot always provide a patent airway in TCS patients.

It was anticipated that we would fail to perform oral intubation under direct laryngoscopy without glottic exposure in our patient. Thus, no attempt was made to do oral intubation under direct laryngoscopy because of the MCLS grade 4 view. Besides LMA, the fiberoptic intubation technique also plays a role in managing the pediatric difficult airway. It is beyond doubt that oxygenation should be maintained during airway manipulation. In our case, with the cooperation of two anesthesiologists to share the task, one performing ventilation with the endoscopic mask and the other executing nasal endoscopic intubation, the placement of the ETT was smoothly done. In an adult case, oxygen delivery either through the working channel of the fiberoptic bronchoscope or with an endoscopic mask would suffice for oxygenation.⁸

Many airway devices have been developed to manage the difficult airway, such as the illuminating stylet (lightwand) and videolaryngoscope (GlideScope, Pentax). However, Shikani Optical stylet (SOS) and Glidescope have been reported to manage pediatric difficult airway successfully.¹³⁻¹⁵ The SOS combines the features of a fiberoptic bronchoscope and a lightwand. Shukry et al reported the application of SOS in facilitating the tracheal intubation of children with craniofacial and mandibulofacial malformations.¹⁴ Pfitzner et al also presented their initial successful experience in the use of SOS in managing children with potential difficult intubation for new users.¹⁵ The feasibility of the lightwand in man aging pediatric mandibulofacial malformations is lacking in the literature and its semi-blind character may not be a suitable option in such a situation.

We chose a CAEC to facilitate extubation, but our patient found the technique difficult to tolerate. Tracheostomy was reluctantly done to avoid prolonged tracheal intubation after two attempts at extubation with the assistance of a CAEC. A CAEC is a long, small-diameter, hollow, and semi-rigid catheter which is designed for exchanging ETTs and can be inserted through an in situ ETT before tracheal extubation. Extubation and subsequent reintubation over a CAEC have been successfully demonstrated in both adult and pediatric ICU.^16,17 Furthermore, a CAEC can be well tolerated even in clearly conscious patients, especially in nasoendotracheal intubation. Wise-Faberowski and Nargozian reported that 25% of children who had been extubated were reintubated in the ICU with the assistance of the CAEC.¹⁶ Tracheostomy was required at some stage in childhood in 41% of children with TCS, and the ratio increased to 84% in TCS patients who also had choanal atresia or stenosis.³

Both inhalational and i.v. induction techniques could successfully preserve spontaneous respiration in TCS patients. The induction agents included sevoflurane only, ketamine only and propofol with sevoflurane or fentanyl.^2,6,12,18 However, our patient sustained severe upper airway obstruction after sevoflurane inhalation in the wake of i.v. induction. The currently used agents for sedation for fiberoptic intubation such as benzodiazepines, propofol, or opioids have their limitations. Therefore, the induction agents for a TCS patient should only be given in the operating room and devices for emergency airway surgery should be ready. Dexmedetomidine was reported to provide a moderate level of conscious sedation without causing respiratory distress or hemodynamic instability during fiberoptic intubation. Dexmedetomidine only or with concurrent low-dose ketamine could provide sedation and comfort to facilitate conscious fiberoptic intubation for a difficult airway in adult patients.^17,18 Further investigations are required for its application in the pediatric difficult airway, particularly concerning the safety aspect.

We conclude that the key points in managing the difficult airway in TCS patients are to maintain spontaneous respiration and use sophisticated skills in FNI. If an endoscopic mask is unavailable, the tech nique would be to maintain mask ventilation and perform FNI carefully until the intubation is successful. New induction agents such as dexmedetomidine which are unlikely to cause respiratory depression may be valuable. Furthermore, a CAEC insertion is recommended to facilitate extubation, and tracheostomy may be indicated if persistent upper airway obstruction occurs after extubation.