Evaluation of the Intubating Laryngeal Mask Airway (ILMA) as an intubation conduit in patients with a cervical collar simulating fixed cervical spine

Abstract

Background: Cervical spine immobilisation with a semi-rigid cervical collar imposes difficulty in tracheal intubation. There is increasing use of the Intubating Laryngeal Mask Airway (LMA- FastrachTM) for intubation in patients with difficult airways. The present study was conducted to assess its potential role for tracheal intubation in simulated fixed cervical spine patients.

Method: After obtaining approval from the ethics committee and patients’ consent, this observational study was performed on 35 adult patients of either sex of ASA physical status I and II scheduled to undergo surgery under general anaesthesia requiring tracheal intubation. A two-piece semi-rigid cervical collar of appropriate size was positioned around the neck of patients. A standard anaesthesia protocol comprising glycopyrrolate, propofol and vecuronium was used for induction of anaesthesia. ILMA placement and blind tracheal intubation through this was attempted by using dedicated silicone tube provided with the ILMA set. Success rate, number of attempts required, time taken, difficulties encountered and any complication that occurred were noted. Anaesthesia was maintained with isoflurane in oxygen and nitrous oxide, pethidine and vecuronium. Following completion of surgery, neuromuscular blockade was reversed with glycopyrrolate and neostigmine.

Results: The overall success rate was 85.7% and the success rate for ILMA placement at first attempt was 57.1%. Tracheal intubation was successful at first attempt in 70.5% of patients. The time taken for ILMA placement and tracheal intubation through this was 31.76 ± 9.74 and 34.04 ± 12.68 seconds respectively. Decreased mouth opening due to presence of the collar led to difficulty in ILMA placement.

Conclusions: Blind tracheal intubation through ILMA is a possible option for airway management in patients with a semi-rigid cervical collar.

Keywords: cervical collar, difficult airway, ILMA, intubation