Acta Anaesthesiol Scand 2000; 44: 1002–1006 Copyright C Acta Anaesthesiol Scand 2000 Printed in Denmark. All rights reserved ACTA ANAESTHESIOLOGICA SCANDINAVICA ISSN 0001-5172 Light-guided intubation via the intubating laryngeal mask using a prototype illuminated flexible catheter Clinical experience in 400 patients V. DIMITRIOU and G. S. VOYAGIS Departments of Anaesthesia, Gennimatas and Sotiria Hospitals, Athens, Greece Background: The transillumination of the soft tissues of the neck using lighted stylets has been used as an aid for tracheal intubation. We evaluated the efficacy and safety of a prototype illuminated flexible catheter to facilitate light-guided intubation through the intubating laryngeal mask. Methods: The illuminated flexible catheter consists of a com- pletely flexible thin plastic catheter with a bulb attached to its distal end. The device was placed into a silicone tracheal tube in such a way that the bulb was adjusted at the distal end of the tracheal tube. The tracheal tube preloaded with the device was inserted through the intubating laryngeal mask and, by observ- ing the glow on the neck, was advanced into the trachea. We report our experience with light-guided intubation through the intubating laryngeal mask in 400 ASA grade 1–3 patients under- going general anaesthesia. Results: The intubating laryngeal mask was inserted success- fully in all patients. The overall intubating success rate was C ONVENTIONAL tracheal intubation through the in- tubating laryngeal mask (ILM) is a ‘blind-on- blind’ technique (1), since both the ILM and the tra- cheal tube are inserted without direct vision of the larynx. This blind technique may be time-consuming (2), misplacement may result in trauma (3) and there is a risk of accidental oesophageal intubation (1, 4, 5). Reports in the literature suggest that transillumi- nation of the soft tissues of the neck using lighted stylets is an alternative to laryngoscopic tracheal intu- bation (6, 7). The following study evaluates the effi- cacy and safety of a prototype illuminated flexible catheter to facilitate a light-guided tracheal intubation through the ILM. Materials and methods The illuminated flexible catheter consists of a com- pletely flexible thin plastic catheter without any met- allic component with a bulb attached at its distal end (8). The device is placed into a straight silicone tra- 1002 99.8% (399/400); in 367 (91.8%) cases at the first attempt, in 28 (7%) at the second, in 4 (1%) at the third and in one case (0.2%) at the fifth attempt. There were 27 patients with potentially dif- ficult airways. All these cases were intubated successfully; in 23 of 27 (85.2%) at the first attempt, in 3 of 27 (11.1%) at the second and one of 27 patients (3.7%) at the third attempt. Conclusion: We conclude that the use of the illuminated flexible catheter facilitates the intubation through the intubating lar- yngeal mask. The suggested light-guided intubating method proved to be a simple, safe and effective technique. Received 21 October 1999, accepted for publication 27 March 2000 Key words: Airway devices; airway management; tracheal intu- bation; intubating laryngeal mask; light guided intubation. c Acta Anaesthesiologica Scandinavica 44 (2000) cheal tube in such a way that the bulb is adjusted to the distal end of the tracheal tube (Fig. 1). After institutional approval and patient written consent, we studied 400 consecutive patients, ASA 1– 3, aged 48∫14 (range 18–87) years and weight 70∫19 (range 42–130) kg, undergoing anaesthesia for elective surgical procedures that would normally require tra- cheal intubation. The study was performed in two dif- ferent hospitals over an 8-month period. The follow- ing airway assessments were made before anaes- thesia: Mallampati grade (9), thyromental distance (10) and cervical spine mobility (11). The conjunction of Mallampati grade Ø3 with either thyromental dis- tance 7 cm or a head/neck mobility 90æ was con- sidered as a potentially difficult airway. Patients were excluded if they were at risk of regurgitation-aspir- ation or suffered from severe respiratory disease. The intubation was performed by two anaesthetists who had more than 10 years’ clinical experience in anaesthesia and past experience of more than 50 intu- bations using ILM with the conventional blind tech-