Study objective: To determine whether the laryngeal mask airway has a useful role in the airway management of patients whose cervical spines are immobilized in a rigid cervical collar.
Design: A randomized study comparing the difficulty, rapidity, and success rate of ventilating patients with immobilized cervical spines using a laryngeal mask airway and an endotracheal tube.
Setting: Medical center surgical unit.
Patients: Twenty-eight ASA physical status I and II women scheduled to undergo elective gynecologic surgery requiring general anesthesia.
Interventions: Tracheas of all anesthetized patients were sequentially intubated with an endotracheal tube and had a laryngeal mask inserted in random order.
Measurements and main results: Mouth opening was measured, and a Mallampati classification was made in each subject both with and without a rigid Philadelphia collar in situ. The view at laryngoscopy was recorded. The time taken to insert both devices to allow for satisfactory ventilation and the degree of difficulty encountered were determined. With a cervical collar in situ, mouth opening was reduced up to 60%. The Mallampati assessment and laryngoscopic view were shifted to one suggestive of a more difficult intubation. The time taken to ventilate these patients and the difficulties encountered were significantly less when using the laryngeal mask (p = 0.0001). A successful outcome was more likely following insertion of the laryngeal mask than when attempting intubation with an endotracheal tube.
Conclusions: The laryngeal mask airway compared favorably with an endotracheal tube in success rate, difficulty of insertion, and time to position correctly in this patient population. Although the laryngeal mask does not reliably protect against aspiration, we believe it may play a useful role if more conventional methods of airway management fail. Further studies in the trauma scenario are indicated.