Background: Since the introduction of the laryngeal mask airway (LMA) into the United States in 1991, the device has become widely used in anesthesia practice. The purpose of this economic analysis was to use existing data to evaluate the costs of the LMA relative to three other common airway management techniques and to identify the variables that had the greatest effect on cost efficiency.
Methods: We evaluated four airway management techniques for healthy adults receiving an isoflurane-nitrous oxide-oxygen anesthetic for elective outpatient surgery: (1) LMA with spontaneous ventilation; (2) face mask with spontaneous ventilation; (3) tracheal intubation after succinylcholine with subsequent spontaneous ventilation; and (4) tracheal intubation after nondepolarizing neuromuscular blockade and controlled ventilation. We analyzed published clinical studies of the LMA and obtained cost data from Stanford University Medical Center. The best available estimates of the independent variables were incorporated into a baseline case. For each airway technique we derived cost equations that excluded costs common to all four techniques.
Results: Relative to airway management with an LMA, calculated values for the baseline analysis included additional isoflurane costs for use of a face mask ($ 0.12/min) and for tracheal intubation with ($ 0.043/min) and without neuromuscular blockade ($ 0.06/min). With a neuromuscular blocking drug cost of $ 0.21/min and an LMA cost per use of $ 20, the face mask with spontaneous ventilation was the cost-efficient airway choice for anesthetics lasting as long as 100 min. Increasing the LMA reuse rate from 10 to 25 made the LMA the least costly airway technique for cases lasting more than 70 min.
Conclusions: If the LMA is reused 40 times, the LMA is the cost-efficient airway choice for outpatients receiving an isoflurane-nitrous oxide-oxygen anesthetic lasting longer than 40 min. This finding does not change if the cost of neuromuscular blockade or the incidence of airway-related complications is varied over a clinically relevant range.