Intubating laryngeal mask airway allows tracheal intubation when the cervical spine is immobilized by a rigid collar

Background. An intubating laryngeal mask airway (ILMA) facilitatestracheal intubation with the neck in neutral position, whichis similar to the neck position maintained by a rigid cervicalcollar. However, a cervical collar virtually obliterates neckmovement, even small movements that normally facilitate airwayinsertion. We therefore tested the hypothesis that the ILMAwill allow tracheal intubation even in patients wearing a rigidcervical collar. Methods. We performed blind tracheal intubation via an ILMAunder general anaesthesia in 50 patients with a rigid Philadelphiacollar in place undergoing cervical spine surgery and 50 generalsurgical patients. Time required for intubation, intubationsuccess rate, and numbers and type of adjusting manoeuvres usedwere recorded. Results. Inter-incisor distance was significantly smaller (4.1(0.8) vs 4.6 (0.7) cm, mean (SD), P<0.01) and Mallampatiscores were significantly greater (P<0.001) in the patientswith collars. ILMA insertion took longer (30 (25) vs 22 (6)s), more patients required two insertion attempts (15 vs 3;P<0.005), and ventilation adequacy with ILMA was worse (P<0.05)in collared patients. However, there were no significant differencesbetween the collars and control patients in terms of total timerequired for intubation (60 (41) vs 50 (30) s), number of intubationattempts, overall intubation success rate (96 vs 98%), or theincidence of intubation complications. Conclusions. Blind intubation through an ILMA is thus a reasonablestrategy for controlling the airway in patients who are immobilizedwith a rigid cervical collar.