Topical lidocaine improves conditions for laryngeal mask airway insertion.

摘要

PURPOSE: We hypothesized that optimal laryngeal mask airway (LMA) insertion conditions might be achieved with topical lidocaine and a smaller dose of propofol. In this study, insertion conditions after topical lidocaine 40 mg followed by propofol 2 mg.kg(-1) were compared with propofol 2 mg.kg(-1) or propofol 3 mg.kg(-1) alone. METHODS: Ninety patients were recruited for this randomized prospective double-blind study. One group received four sprays of topical lidocaine (40 mg) over the posterior pharyngeal wall followed by propofol 2 mg.kg(-1) (Group 2PL; n = 30). The other two groups received four sprays of 0.9% normal saline followed by propofol 2 mg.kg(-1) (Group 2P; n = 30) or by propofol 3 mg.kg(-1) (Group 3P; n = 30). The frequency of optimal insertion conditions (successful insertion at the first attempt without adverse responses) and side effects were recorded. RESULTS: The frequency of optimal insertion conditions was greater in Group 2PL (20/30, 67%) and Group 3P (22/30, 73%) than in Group 2P (11/20, 37%) (P = 0.009). In Group 3P, the mean blood pressure was lower than in the other groups prior to LMA-Classic insertion (P = 0.003) but was similar after insertion. The incidence of apnea was greater in Group 3P patients (17/30, 57%) than in Group 2P (2/30, 7%) or Group 2PL patients (1/30, 3%) (P < 0.001). CONCLUSION: Topical lidocaine 40 mg followed by propofol 2 mg.kg(-1) can provide optimal insertion conditions of the LMA-Classic comparable to those of propofol 3 mg.kg(-1), with fewer hemodynamic changes and a lower incidence of apnea.