Bispectral Index for Improving Anesthetic Delivery and Postoperative Recovery

BACKGROUND: The use of clinical signs may not be reliable for measuring the hypnotic component of anesthesia. The use of bispectral index (BIS) to guide the dose of anesthetics may have certain advantages over clinical signs. OBJECTIVES: Our objective in this review was to assess whether BIS reduced anesthetic use, recovery times, recall awareness, and cost. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 2), MEDLINE (1990 to May 2007), EMBASE (1990 to May 2007), and reference lists of articles. SELECTION CRITERIA: We included randomized controlled trials comparing BIS with clinical signs in titrating anesthetics. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality, extracted data, and analyzed the data. We contacted study authors for further details. MAIN RESULTS: We included 20 studies with 4056 participants. Seven recent trials are still awaiting assessment. BIS-guided anesthesia reduced the requirement for propofol by 1.30 mg · kg−1 · h−1 [578 participants; 95% confidence interval (CI) −1.97 to −0.62] and for volatile anesthetics (desflurane, sevoflurane, and isoflurane) by 0.17 minimal alveolar concentration equivalents (689 participants; 95% CI: −0.27 to −0.07). Irrespective of the anesthetic, BIS reduced the recovery times: time for eye opening by 2.43 min (996 participants; 95% CI: −3.60 to −1.27), response to verbal command by 2.28 min (717 participants; 95% CI: −3.47 to −1.09), time to tracheal extubation by 3.05 min (1057 participants; 95% CI: −3.98 to −2.11), and orientation by 2.46 min (316 participants; 95% CI: −3.21 to −1.71). BIS shortened the duration of postanesthesia care unit stay by 6.83 min (584 participants; 95% CI: −12.08 to −1.58) but did not reduce time to home readiness (329 participants; 95% CI: −30.11 to 16.09). The BIS-guided anesthesia significantly reduced the incidence of intraoperative recall awareness in surgical patients with high risk of awareness (odds ratio, 0.20; 95% CI: 0.05–0.79). AUTHORS’ CONCLUSIONS: Anesthesia guided by BIS within the recommended range (40–60) could improve anesthetic delivery and postoperative recovery from relatively deep anesthesia. In addition, BIS-guided anesthesia has a significant impact on reduction of the incidence of intraoperative recall in surgical patients with a high risk of awareness. The full review is available: Punjasawadwong Y, Boonjeungmonkol N, Phongchiewboon A. Bispectral index for improving anesthetic delivery and postoperative recovery. Cochrane Database Syst Rev 2007, Issue 4. Art. No.: CD003843. DOI: 10.1002/14651858.CD003843.pub2.