Clinical observation on inhalation induction with sevoflurane for insertion of laryngeal mask airway in elderly patients

Abstract

Objective To compare the clinical efficacy and safety of anesthesia induction between inhalation of sevoflurane and intravenous injection of propofol for laryngeal mask airway (LMA) insertion in elderly patients.Methods 40,ASA physical grade Ⅰ ～ Ⅱ patients scheduled to receive elective total knee arthroplasty were allocated to 2 groups at random. Patients in group one( G1 ) received intravenous induction of propofol infusion by a targetcontrolled infusion system which was set at the effect-site concentration of 4.0μg/ml,while patients in group two(G2)received inhalational induction with sevoflurane using vital capacity manoeuver at the target of end-expiratory concentration of 3.0％. We observed the whole procedure of anesthesia induction and LMA insertion, while recording the changes in hemodynamic state and occurrence of adverse events. Results More than 85％ patients achieved LMA insertion at first attempt using either induction manoeuver. Although consciousness loss time in G1 was 39. ls longer than G2, there was no difference in anesthesia induction time for LMA insertion between these two groups. Contrary to a significant decrease in MAP following induction for patients in G1, there appeared hemodynamically stable in patients of G2,while apnea also significantly seldom occurred in G2 as compared to G1 (20％ vs 85％ ,P ＜0. 05).Conclusion As compared to intrvenous induction with propofol, inhalation induction with sevoflurane provided a valuable alternative for LMA insertion in adults. Key words: Elderly; Sevoflurane; Inhalational induction; Propofol; Laryngeal mask airway (LMA)