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

Abstract

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 ≥ 9 were attained in similar times. AAI monitoring can improve titration of and recovery from sevoflurane for LAGB.

Non-instrumental clinical monitoring does not guarantee an adequate course of general anesthesia. A prospective clinical study

“…During induction of anesthesia, together with decrease in AAI, in both groups also heart rate and systemic blood pressure decreased. The observations of Freo et al were similar 27 . During induction of anesthesia, the AAI was always decreased; however other clinical parameters varied.…”

“…AAI was more stable in VOL group. However, lower values of AAI during volatile anesthesia may indicate that volatile anesthetics were overdosed 27 . Intraoperative monitoring of level of anesthesia can reduce the consequences of neurotoxicity of anesthetics 14,15,43,44 .…”

“…Mean values of AAI after reversal of anesthesia was 60 in both groups, similarly to values observed before the induction of anesthesia. Because there was a good correlation between the level of conscience and AAI, use of neuromonitoring during anesthesia makes the prediction of the time of recovery over anesthesia more simple 39,41,46,47 and can reduce period between end of anesthesia and extubation 22,27,31,48,49 . The episodes of intraoperative awareness were surveyed using a questionnaire based on the work of Brice 29 , because of its efficacy and large number of studies 50 .…”

“…The costs of hospitalization and the incidence of postoperative nausea and vomiting were also decreased. Moreover, the patients' postoperative level of consciousness was better 14,26,27 . The objective of the study was (1) to compare the value of basic clinical parameters and simultaneously recorded AEP for analysis of the depth of both total intravenous and volatile anesthesia, and (2) incidence of intraoperative awareness.…”

Society of Anesthesia and Sleep Medicine Guideline on Intraoperative Management of Adult Patients With Obstructive Sleep Apnea

“…Another intervention, possibly promoting increased safety in OSA, is the intraoperative monitoring of anesthesia depth. This has been suggested by Ibraheim et al 172 and Freo et al, 173 who demonstrated that monitoring for titration of levels of inhalational agents reduced the required anesthetic dosage and improved the postanesthetic recovery in patients with obesity.…”