Stylet-Assisted Tracheal Intubation Through an ILMA in a Patient with an Anterior Larynx

Abstract

To the Editor Although the intubating laryngeal mask airway (ILMA) has been described for use in morbidly obese patients,1 despite its correct placement, tracheal intubation may be unsuccessful. An obese male patient (body mass index [BMI] = 34) in the intensive care unit with a right middle cerebral artery territory stroke required urgent tracheal intubation owing to poor Glasgow coma scale (E1V1M2). After sedation and paralysis, ventilation via a mask was adequate but intubation using a #4 Macintosh blade, external laryngeal manipulation, and a bougie was not possible. An ILMA (#4 LMA-Fastrach™, The Laryngeal Mask Company Limited, Le Rocher, Victoria, Mahé, Seychelles) was placed and ventilation resumed. Tracheal intubation using the flexometallic tube provided with the ILMA failed as the tube tip was repeatedly displaced into the esophagus. Repositioning of the ILMA and Chandy's maneuver part 22 were attempted but also unsuccessful. Intubation with a 7.0-mm internal diameter cuffed Portex polyvinyl chloride (PVC) endotracheal tube (ETT) (Smiths Medical, UK), together with a flexion maneuver, also did not help because of the anteriorly positioned larynx. Size 5 ILMA and Fiberoptic Bronchoscope were unavailable. Hence, using a stylet, the tip of the portex tube was bent as shown in Figure 1 and reintroduced through ILMA, and the ETT could be easily advanced off the stylet into the trachea.Figure 1: Angle of emergence formed by the tracheal tubes on emerging from the distal aperture of the intubating laryngeal mask airway (ILMA). A, LMA-Fastrach silicone wire-reinforced tube (7.5-mm internal diameter). B, Portex polyvinyl chloride tracheal tube (7.5-mm internal diameter). C, Portex polyvinyl chloride tracheal tube with stylet (PVCT; 7.5-mm internal diameter).In cases of extremely anterior larynx, accentuating the angle of emergence of the tracheal tube from the ILMA may facilitate intubation.3 This may be safely done by ensuring that the tip of the stylet remains within the ETT, about 1 to 2 cm proximal to the tip of ETT. We measured the angle of emergence (using a protractor) of Flexometallic and Portex PVC ETT through ILMA and found them to be 35° and 45°, respectively (Fig. 1A & 1B). Introducing a stylette as suggested increases the angle of emergence to 65° (Fig. 1C), which aids in placement of the tracheal tube tip through ILMA in patients with anterior larynx. Damage to the arytenoids and trachea is a potential complication of blind intubation. Difficulty in advancing the tube due to impingement upon the anterior surface of the larynx is another possibility. Using the Parker flexitip PVC tube is an option in this scenario. The centered, tapered, and flexible distal tip gently flexes when resistance is encountered, thus enabling successful introduction minimizing airway trauma.4 Patient consent statement Written permission from the patient's first degree relative was obtained because the patient passed away at home owing to unrelated causes, months after treatment, prior to this submission. The written consent statement is available from the archival author. Georgene Singh, MD Appavoo Arulvelan, MD Kadarapura N. Gopalakrishna, MD Sethuraman Manikandan, MD Vimala Smita, MD, DM Ramesh C. Rathod, MD Department of Anesthesiology Sree Chitra Tirunal Institute for Medical Sciences and Technology Thiruvananthapuram Kerala, South India [email protected]