Bispectral Index for Improving Anesthetic Delivery and Postoperative Recovery

Chiang Mai University, Department of Anesthesiology, Faculty of Medicine, Chiang Mai, Thailand, 50200.
Cochrane database of systematic reviews (Online) (Impact Factor: 6.03). 02/2007; 4(4):CD003843. DOI: 10.1002/14651858.CD003843.pub2
Source: PubMed


The results from this updated review indicate that BIS can be useful in guiding the anaesthetic dose to avoid the risk of intraoperative awareness in surgical patients at high risk for awareness. Furthermore, anaesthesia guided by BIS improves anaesthetic delivery and recovery from anaesthesia. General anaesthesia requires multiple agent administration to achieve unconsciousness (hypnotics), muscle relaxation, analgesia and haemodynamic control. Many anaesthesiologists rely on clinical signs alone to guide anaesthetic management. BIS is a scale derived from the measurement of cerebral electrical activity in anaesthetized patients so that the level of anaesthesia and drug delivery can be optimised. We systematically reviewed 36 randomized controlled studies to find out whether BIS could reduce the risk of intraoperative awareness and reduce anaesthetic use and recovery times in adult surgical patients. The risk of intraoperative awareness was determined in selected patients who were at potentially high risk for awareness. Four studies (7761 patients) that used clinical signs as a guide to anaesthetic administration in standard practice, as the control group, demonstrated a significant reduction in the risk of awareness with BIS monitoring. Four studies (26,530 patients) compared BIS monitoring with end tidal anaesthetic gas (ETAG) monitoring as a guide to management of anaesthesia and they did not demonstrate any difference in terms of intraoperative awareness. There was an overall reduction in volatile anaesthetic dose and the dose of propofol in the BIS group. Recovery from anaesthesia was quicker and postanaesthesia recovery care unit stay was shorter. The limitations of some of the clinical trials on BIS are discussed.

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    • "Proponents of the use of processed EEG for monitoring depth of anesthesia argue that these monitors allow precise titration of anesthetic levels, thereby reducing total amounts of anesthetic, reducing postanesthesia recovery time, and improving quality of recovery from a patient’s perspective.59 Processed EEG-guided anesthesia has also been shown to reduce the incidence of intraoperative recall in patients at high risk for awareness.60 Other trials, however, failed to show benefit of processed EEG-guided anesthesia. "
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    ABSTRACT: Anesthesiologists are unique among most physicians in that they routinely use technology and medical devices to carry out their daily activities. Recently, there have been significant advances in medical technology. These advances have increased the number and utility of medical devices available to the anesthesiologist. There is little doubt that these new tools have improved the practice of anesthesia. Monitoring has become more comprehensive and less invasive, airway management has become easier, and placement of central venous catheters and regional nerve blockade has become faster and safer. This review focuses on key medical devices such as cardiovascular monitors, airway equipment, neuromonitoring tools, ultrasound, and target controlled drug delivery software and hardware. This review demonstrates how advances in these areas have improved the safety and efficacy of anesthesia and facilitate its administration. When applicable, indications and contraindications to the use of these novel devices will be explored as well as the controversies surrounding their use.
    Full-text · Article · Mar 2014 · Medical Devices: Evidence and Research
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    • "The routine approach for evaluating the depth of anesthesia is the assessment of hemodynamic parameters and subjective signs such as movement, sweating, and lacrimation, which are not adequately sensitive and specific.7 Since 1977, several studies have sought to determine whether Bispectral Index (BIS) monitoring is a reliable tool for the analysis of the anesthetic depth.8 An FDA-approved method, the BIS is adequately sensitive for the evaluation of the depth of anesthesia and is believed to be useful for the detection of light anesthesia by processing the patient’s electroencephalogram (EEG).9,10 "
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    ABSTRACT: Background: Awareness and recall, though not common, are the major hazards of general anesthesia, especially in Cesarean section (C/S) because of the absence of benzodiazepine and opioids for a significant time during anesthesia. In this study, the Bispectral Index (BIS), end-tidal isoflurane, and hemodynamic parameters were examined to evaluate the depth of the routine general anesthetic technique in C/S. Methods: This study was carried out on 60 parturient patients undergoing elective C/S. A standardized anesthetic technique was applied: induction with Thiopental (4-5 mg/kg) and Succinylcholine (1.5-2 mg/kg) as well as maintenance with O2, N2O, and isoflurane. Electrocardiogram, heart rate, blood pressure, Spo2, end-tidal isoflurane concentration, BIS, and any clinical signs of inadequate depth of anesthesia such as movement, sweating, lacrimation, coughing, and jerking were continuously monitored and recorded at 16 fixed time points during anesthesia. Results: A median BIS of less than 70 (range: 42-68) was obtained on all occasions during surgery; however, at each milestone, at least 20% of the patients had BIS values above 60. Hemodynamic parameters increased significantly in some patients, especially during laryngoscopy and intubation. No patient experienced recall or awareness. Conclusion: The currently used general anesthetic technique in our center appears inadequate in some milestones to reliably produce BIS values less than 60, which are associated with lower risk of awareness. Therefore, with respect to such desirable outcomes as good Apgar and clinical status in neonates, we would recommend the application of this method (if confirmed by further studies) through larger dosages of anesthetic agents.
    Full-text · Article · Sep 2013 · Iranian Journal of Medical Sciences
    • "The use of clinical signs may not reliably measure the hypnotic component of anesthesia, as they can be affected by factors such as blood volume, cardiac contractility, and drug effects on the cardiovascular system.[7] Bispectral index (BIS) provides a continuous age-independent monitoring of hypnotic state induced by the most widely used sedative-hypnotic agent and has been used to assess the induction quality, depth of anesthesia, intraoperative requirement of anesthetics, postoperative recovery, and to reduce the incidence of intraoperative recall awareness.[8–11] BIS value of 0 represents an isoelectric electroencephalogram and 100 represents an awake state, whereas 40 to 60 reflect adequate hypnotic effect for general anesthesia. "
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    ABSTRACT: Intraoperative depth of anesthesia may affect postoperative pain relief. This prospective, randomized, and observer-blinded study assessed the effect of intraoperative depth of anesthesia on the postoperative pain and analgesic requirements in patients undergoing laparoscopic cholecystectomy. A total of 80 patients were randomly divided into two groups of 40 each. A standard technique for anesthesia was followed in all patients. Depth of anesthesia was monitored by bispectral index (BIS) and adjusted with 0.5 to 1.5% isoflurane in group S by addition of propofol in group B, if required, to maintain a BIS value of 45 to 40. Postoperative analgesia was provided by tramadol 1 mg/kg every 6 hours and rescue analgesia by morphine boluses. Postoperative pain was assessed by Visual analogue scale score at 0, 8, 16, and 24 hours. The demographic characteristics were comparable in both groups. The mean BIS value in Group S was 63.32 ± 11.43 and 45.06 ± 15.31 in Group B, well in the range of 40 to 60, reflecting adequate hypnotic effect for general anesthesia. The mean arterial pressure was low in group B throughout the surgery (P<0.05-0.001). The pain score were lower in group B at 0 and 8 hours postoperatively when compared with group S (P<0.05). The rescue analgesic requirement was less in group B, compared with group S (P<0.05). Maintaining BIS to a value of 45 to 40 throughout the surgery results in better postoperative pain relief and decreased requirement of rescue analgesic without any untoward effect.
    No preview · Article · Oct 2011 · Journal of Anaesthesiology Clinical Pharmacology
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