Effects of A-Line Autoregression Index (AAI) Monitoring on Recovery After Sevoflurane Anesthesia for Bariatric Surgery

Monitoring depth of anesthesia may improve anesthetic dosing and postanesthetic recovery in obese patients. Sixty morbidly obese patients undergoing laparoscopic adjustable gastric bandage (LAGB) were randomly assigned to receive anesthesia with sevoflurane titrated by either standard clinical parameters (SCP) (target = baseline hemodynamic parameters +/- 20%) or by A-line ARX index (AAI) (target = 20 +/- 5). Heart rate, arterial blood pressure, inspiratory and expiratory gas concentrations, and AAI were recorded in all patients at 5-min intervals, but AAI was made available only to the anesthesiologist assigned to AAI-monitored patients. Emergence times in surgery room and recovery times in postanesthesia care unit (PACU) were recorded at 1- and 30-min intervals. Mean intraoperative values of AAI were higher in AAI-monitored than in SCP-monitored patients (22.5 vs 15.0, p = 0.001). Compared to SCP monitoring, AAI monitoring reduced consumption of sevoflurane by 20% (p = 0.014), times to eye opening by 2.4 min (p = 0.001) and to extubation by 2.5 min (p = 0.009) and to achieve SpO(2) 92% in room air by 17 min (p = 0.001). Aldrete scores were higher in AAI- than in SCP-monitored patients at arrival in PACU (p = 0.035), but Aldrete scores a parts per thousand yen9 were attained in similar times. AAI monitoring can improve titration of and recovery from sevoflurane for LAGB.