BIS Monitoring on Intraoperative Awareness: A Meta-analysis

Abstract

Intraoperative awareness is a very serious complication of general anesthesia. Several studies have evaluated the potential association between bispectral index (BIS) and intraoperative awareness, however, the results obtained were controversial. Therefore, we performed a meta-analysis to further assess the association between the BIS monitoring and the incidence of intraoperative awareness. A comprehensive search was conducted to identify all eligible studies from the online literature databases published prior to Feb. 2017. A total of five studies with 17 432 cases and 16 749 controls were included. An odds ratio (OR) and a 95% confidence interval (CI) were calculated to examine the strength of the association. The results showed that in the overall analysis, the association between the BIS monitoring and the incidence of intraoperative awareness was not significant (OR=0.58, 95% CI= 0.22–1.58, P=0.29). A stratified analysis by comparing different anesthesia methods revealed that BIS monitoring group showed a lower incidence of intraoperative awareness in patients with intravenous anesthesia when compared with non-BIS monitoring group (OR=0.20, 95% CI=0.08–0.49, P=0.0004), whereas there was no statistically significant difference in the incidence of intraoperative awareness between BIS and non-BIS monitoring groups in patients with inhalation anesthesia (OR=1.13, 95% CI=0.56-2.26, P=0.73). In conclusion, our meta-analysis showed that BIS monitoring had no appreciable advantage in the reduction of the intraoperative awareness incidence in inhalation anesthesia, while showed a remarkable superiority in intravenous anesthesia.

Keywords

bispectral index / intraoperative awareness / general anesthesia / meta-analysis

References

[1] BestasA, YasarMA, BayarMK, et al.. The effects of two different anaesthesia techniques on bispectral index values and awareness during off-pump coronary artery bypass grafting. J Clin Monit Comput, 2004, 18(5-6): 347-351

[2] MashourGA, TremperKK, AvidanMS. Protocol for the “Michigan Awareness Control Study”: a prospective, randomized, controlled trial comparing electronic alerts based on bispectral index monitoring or minimum alveolar concentration for the prevention of intraoperative awareness. BMC Anesthesiol, 2009, 9: 7

[3] DeeproseC, AndradeJ, HarrisonD, et al.. Unconscious auditory priming during surgery with propofol and nitrous oxide anaesthesia: a replication. Br J Anaesth, 2005, 94(1): 57-62

[4] Prys-RobertsC. Anaesthesia: a practical or impractical construct. Br J Anaesth, 1987, 59(11): 1341-1345

[5] SamuelssonP, BrudinL, SandinRH. Late psychological symptoms after awareness among consecutively included surgical patients. Anesthesiology, 2007, 106(1): 26-32

[6] SandinRH, EnlundG, SamuelssonP, et al.. Awareness during anaesthesia: a prospective case study. Lancet, 2000, 355(9205): 707-711

[7] SebelPS, BowdleTA, GhoneimMM, et al.. The incidence of awareness during anesthesia: a multicenter United States study. Anesth Analg, 2004, 99(3): 833-839

[8] XuL, WuAS, YueY. The incidence of intra-operative awareness during general anaesthesia in China: a multi-centre observational study. Acta Anaesthesiol Scand, 2009, 53(7): 873-882

[9] American Society of Anesthesiologists Task Force on Intraoperative Awareness. Practice advisory for intraoperative awareness and brain function monitoring: a report by the american society of anesthesiologists task force on intraoperative awareness. Anesthesiology, 2006,104(4):847-864

[10] JohansenJW. Update on bispectral index monitoring. Best Pract Res Clin Anaesthesiol, 2006, 20(1): 81-99

[11] PunjasawadwongY, BoonjeungmonkolN, PhongchiewboonA. Bispectral index for improving anaesthetic delivery and postoperative recovery. Cochrane Database Syst Rev, 2007, 4: CD003843

[12] MashourGA, ShanksA, TremperKK, et al.. Prevention of intraoperative awareness with explicit recall in an unselected surgical population: a randomized comparative effectiveness trial. Anesthesiology, 2012, 117(4): 717-725

[13] ZhangC, XuL, MaYQ, et al.. Bispectral index monitoring prevent awareness during total intravenous anesthesia: a prospective, randomized, double-blinded, multi-center controlled trial. Chin Med J (Engl), 2011, 124(22): 3664-3669

[14] AvidanMS, JacobsohnE, GlickD, et al.. Prevention of intraoperative awareness in a high-risk surgical population. N Engl J Med, 2011, 365(7): 591-600

[15] AvidanMS, ZhangL, BurnsideBA, et al.. Anesthesia awareness and the bispectral index. N Engl J Med, 2008, 358(11): 1097-1108

[16] MylesPS, LeslieK, McNeilJ, et al.. Bispectral index monitoring to prevent awareness during anaesthesia: the B-Aware randomised controlled trial. Lancet, 2004, 363(9423): 1757-1763

[17] StoppeC, PetersD, FahlenkampAV, et al.. aepEX monitor for the measurement of hypnotic depth in patients undergoing balanced xenon anaesthesia. Br J Anaesth, 2012, 108(1): 80-88

[18] LiuSS. Effects of bispectral index monitoring on ambulatory anesthesia: a meta-analysis of randomized controlled trials and a cost analysis. Anesthesiology, 2004, 101(2): 311-315

[19] LeslieK, MylesPS, ForbesA, et al.. Recovery from bispectral index-guided anaesthesia in a large randomised controlled trial of patients at high risk of awareness. Anaesth Intensive Care, 2005, 33(4): 443-451

[20] LeslieK, MylesPS, ChanMT, et al.. Severe postoperative nausea and vomiting in a randomized trial of nitrous oxide-based versus nitrous oxide-free anesthesia. Br J Anaesth, 2008, 101(4): 498-505

[21] RampersadSE, MulroyMF. A case of awareness despite an “adequate depth of anesthesia” as indicated by a Bispectral Index monitor. Anesth Analg, 2005, 100(5): 1363-1364

[22] MychaskiwG 2, HorowitzM, SachdevV, et al.. Explicit intraoperative recall at a Bispectral Index of 47. Anesth Analg, 2001, 92(4): 808-909

[23] MessinaAG, WangM, WardMJ, et al.. Anaesthetic interventions for prevention of awareness during surgery. Cochrane Database Syst Rev, 2016, 10: CD007272

[24] Ahmad T, Sheikh NA, Akhter N, et al. Intraoperative Awareness and Recall: A Comparative Study of Dexmedetomidine and Propofol in Cardiac Surgery. Cureus, 2017,9(8):e1542

[25] CascellaM. Mechanisms underlying brain monitoring during anesthesia: limitations, possible improvements, and perspectives. Korean J Anesthesiol, 2016, 69(2): 113-120

[26] MarchantN, SandersR, SleighJ, et al.. How electroencephalography serves the anesthesiologist. Clin EEG Neurosci, 2014, 45(1): 22-32