To the Editor:
The Glidescope® video laryngoscope is an effective and well-established device for facilitating tracheal tube placement (1,2) Here we report an unusual complication of Glidescope® assisted intubation.
A 72-yr-old man presented for resection of a thoracic spinal cord arteriovenous malformation. The patient had a past medical history significant for myotonia congenita and hiatal hernia with mild acid reflux. On physical examination he was found to have a Mallampati Class II view of the oropharynx with mouth opening slightly <4 cm and normal range of motion of the cervical spine. In addition, review of his previous records revealed that during a prior anesthetic he had a Cormack–Lehane Grade 3 laryngeal view necessitating three direct laryngoscopy attempts and the use of an intubating stylet to secure the airway.
Anesthesia was induced with lidocaine, fentanyl, propofol, and cisatracurium. After 3 min of ventilation via mask, we easily inserted a Glidescope® video laryngoscopy blade and obtained a Grade I view of the vocal cords. An 8.0 mm internal diameter tracheal tube with the manufacturer recommended Rigid Stylet™ was passed through the vocal cords under Glidescope® visualization. The cuff was inflated and positive pressure ventilation through the tube produced a normal end tidal CO2 tracing and bilateral breath sounds.
At this point a small amount of blood was noted in the retropharynx on the Glidescope® monitor. Upon withdrawal of the Glidescope® blade the tracheal tube was seen perforating the right anterior tonsillar pillar. After consulting with an otolaryngologist, we removed the tracheal tube and reintubated the trachea using a fiberoptic laryngoscope without difficulty. The trachea was extubated in the operating room following the procedure, and minimal throat soreness was reported on postoperative day one.
We postulate several mechanisms for this unusual complication:
- After obtaining an adequate view of the vocal cords with the Glidescope®, we blindly passed the tracheal tube through the oropharynx until visualizing the tip of the tube adjacent to the glottic opening on the Glidescope® monitor. It was during this blind pass of the tube that the anterior tonsillar pillar was perforated.
- We used a standard tracheal tube and the manufacturer recommended Rigid Stylet™. The combination of the stylet and the sharp edge of the tracheal tube may have contributed to perforation of the anterior tonsillar pillar.
- Patients with myotonia congenita can be resistant to the effects of nondepolarizing muscle relaxants in the setting of direct stimulation (3). Inadequate relaxation of the palatoglosseus muscle may predispose to anterior tonsillar pillar perforation. The already thin tonsillar pillar membrane may have been pulled taut by palatoglosseus muscle contraction, making it more susceptible to perforation.
To avoid similar complications when using the Glidescope® video laryngoscope we suggest the following:
- Use of a soft-edged endotracheal tube (such as the Parker Flex-Tip™) to avoid damage to pharyngeal structures, especially in conjunction with the Rigid Stylet™. Verathon Medical has recently introduced such a tube for use with the Glidescope® system (GVL® GlideRite™).
- Directly visualize the tracheal tube as it is inserted into the mouth along the curvature of the Glidescope® laryngoscope blade. Only after the tip of the tube has passed out of view should the Glidescope® video monitor be viewed.
Asif M. Malik, MD
Jonathan K. Frogel, MD
Department of Anesthesiology
Henry Ford Hospital
2799 West Grand Blvd.
Detroit, MI 48202
1. Rai MR, Dering A, Verhese C. The Glidescope® system:a clinical assessment of performance. Anaesthesia 2005;60:60–64.
2. Lai HY, Chen IH, Chen A, et al. The use of the Glidescope® for tracheal intubation in patients with ankylosing spondylitis. Br J of Anaesth 2006;97:419–22.
3. Russell SH, Hirsch NP. Anaesthesia and myotonia. Br J of Anaesth 1994;72:210–16.