Comparison of sevoflurane with propofol for laryngeal mask airway insertion in adults

We performed a prospective, randomized, controlled trial to compare the qua lity and ease of laryngeal mask airway (LMA) insertion after either rapid i nhaled sevoflurane or IV propofol induction of anesthesia. Seventy-six unpr emedicated ASA physical status I or II patients were anesthetized with eith er a single vital capacity breath of sevoflurane 8% or IV propofol 3 mg/kg, which produced equally rapid loss of consciousness (40.5 +/- 13.9 vs 37.7 +/- 9.9 s; P > 0.05). The LMA was inserted more rapidly in patients in the propofol group (74 +/- 29 vs 127 +/- 35 s; P < 0.01) and required fewer att empts (1.2 vs 1.6; P < 0.05) than the sevoflurane group. There was a greate r incidence of initially impossible mouth opening in the sevoflurane group (45% vs 21%; P < 0.05). Once mouth opening was possible, the degree of atte nuation of laryngeal reflexes was similar. The overall incidence of complic ations related to LMA insertion, especially apnea (32% vs 0%; P < 0.01), wa s more frequent in the propofol group (82% vs 26%; P < 0.01). There were fo ur failures of LMA insertion in the propofol group and none in the sevoflur ane group. Both groups had stable hemodynamic profiles and good patient sat isfaction. We conclude that sevoflurane vital capacity breath induction com pares favorably with TV propofol induction for LMA insertion in adults. How ever, prolonged jaw tightness after the sevoflurane induction of anesthesia may delay LMA insertion. Implications: Ln this randomized, controlled tria l, we compared the ease of insertion of the laryngeal mask airway in adults after induction of anesthesia with either a sevoflurane vital capacity bre ath technique or propofol IV. We conclude that sevoflurane compares favorab ly with propofol, although prolonged jaw tightness may delay laryngeal mask airway insertion.