Bispectral Index-guided Anesthesia Research Articles

The Impact of Rocuronium and Sugammadex on Length of Stay in Patients Undergoing Open Spine Surgery: A Propensity Score-Matched Analysis.

Enhanced Recovery After Surgery (ERAS), an all-encompassing perioperative care approach, has been demonstrated to enhance surgical results, mitigate postoperative issues, and decrease the length of hospital stay (LOS) in diverse surgical specialties. In this retrospective study, our objective was to examine the influence of muscle relaxant selection on LOS and perioperative results in adult patients undergoing open spine surgery. Specifically, we compared 201 patients who received cisatracurium and neostigmine with 201 patients who received rocuronium and sugammadex, after 1:1 propensity score matching. The utilization of the rocuronium and sugammadex combination in anesthesia for open spinal surgery did not lead to a reduction in the LOS but was associated with a decreased incidence of postoperative chest radiographic abnormalities, including infiltration, consolidation, atelectasis, or pneumonia (p = 0.027). In our secondary analysis, multivariate analysis revealed multiple determinants influencing the prolonged LOS (>7 days) during open spine surgery. Bispectral index-guided anesthesia emerged as a protective factor, while variables such as excessive intraoperative blood loss and fluid administration as well as postoperative chest radiographic abnormalities independently contributed to prolonged LOS.

Combination of olanzapine with bispectral index guided anesthesia to prevent postoperative delirium in elderly patients undergoing major gastrointestinal elective surgery: a randomized, double-blind, placebo-controlled study protocol

Introduction: Postoperative delirium (POD) is an important complication of major surgery in elderly patients. It increases morbidity and mortality, hospital stay, and total healthcare costs. Since no treatment has proven effective once POD is established, prevention is key. Evidence exists that bispectral index guided anesthesia (BIS-GA) and antipsychotics may independently reduce incidence of POD, but the efficacy of combining these preventive strategies is unknown. Objective: To compare the combination of olanzapine + BIS-GA with BIS-GA alone for prevention of POD in elderly patients undergoing major elective surgery.Methods: We propose a Phase II, multi-center, randomized, double-blind, parallel, placebo-controlled trial. The study arms will be BIS-GA + two doses of olanzapine 5mg given pre and postoperatively compared with BIS-GA + placebo in patients ≥65 years hospitalized for major elective surgery. Exclusion criteria include cardiac- and neurosurgery, dementia history, concurrent antipsychotic, anticholinergic, or sedative-hypnotic use, olanzapine allergy, delirium at hospital admission, cognitive impairment and inability to be interviewed. The primary outcome is incidence of POD diagnosed by DSM-V criteria and assessed by the Confusion Assessment Method (CAM) scale. Secondary outcomes include delirium severity, rescue therapy use, length of hospital stay and incidence of adverse events.Discussion: There is an increasing need for trials that advance knowledge in prophylactic methods to prevent delirium. By combining two preventive methods, we expect to decrease the incidence of POD, which will result in decreased morbidity, mortality, and total healthcare costs.

Anesthesia for electroconvulsive therapy

Electroconvulsive therapy (ECT) is a well established and effective therapy in treatment-resistant depression. It is performed under general anesthesia, but no consensus exists regarding the optimal anesthetic drugs. A growing interest in optimizing adjunctive medication regimes in ECT anesthesia has emerged in recent years. Moreover different methods of seizure induction have been evaluated. Pretreatment with dexmedetomidine eased the propofol injection pain and reduced the hyperdynamic response to ECT, but prolonged recovery. Remifentanil exhibited no proconvulsive effect and had no effect on seizure quality. Ketamine showed an antidepressive effect but was associated with cardiovascular side effects and an increased recovery time. A bispectral index-guided anesthesia or a time delay between anesthesia and seizure induction resulted in a better seizure quality presumably by avoiding high concentrations of (anticonvulsive) hypnotics. Seizure induction by magnetism seems to be an alternative to ECT, as the former is associated with less cognitive side effects but comparable antidepressive efficacy. The current practice of anesthesia for ECT should not be modified, as the evidence of studies is either too low or the results are inconsistent. Some approaches are promising but require validation in further studies with a higher number of participants.

Frequency of anesthetic overdose with mean alveolar concentration-guided anesthesia at high altitude

This study reported the frequency of anesthetic overdose measured with the bispectral index in a high altitude city (Bogotá-Colombia, 2600 meters above sea level). We assembled a prospective cohort of patients. Preoperative variables were described, and 10 minutes after the surgical incision, bispectral index, mean alveolar concentration, mean arterial pressure, and oxygen saturation were recorded. Bispectral index was classified as superficial (60), adequate (40–60), and deep (> 40). Mean alveolar concentration was classified as low (< 0.8), normal (0.8–1.2), and high (> 1.2). We included 50 patients. The mean age of the patients was 36.3 ± 13.5 years; 48% were male and 78% were categorized as ASA I. Mean values of mean alveolar concentration and bispectral index were 1.14 ± 0.18 and 38.66 ± 6.9, respectively. Frequency of anesthetic overdose measured with bispectral index was 54% and only 20% with mean alveolar concentration. In total, 78% of patients received normal mean alveolar concentration values, and among these patients, 49% had deep bispectral index levels and 51% were adequate. There was no correlation between mean alveolar concentration and bispectral index (Pearson r = 0.161, P = 0.246) or between bispectral index and mean arterial pressure (Pearson r = 0.367, P = 0.08). All patients older than 60 years exhibited deep bispectral index levels, and although we did not identify a correlation between age and bispectral index, a tendency was observed (Pearson r = –0.087, P = 0.538). Safe and effective anesthesia overdose could be a common phenomenon. Bispectral index-guided anesthesia could be a helpful and reliable tool in the assessment and prevention of anesthesia overdose at high altitude. The study was approved by the ethics committee of the Fundación Cardioinfantil-Instituto de cardiología, Bogota, Colombia (approved number: 312017).

Effect of adjunctive dexmedetomidine on anesthesia and analgesia requirement and recovery characteristics during Bispectral Index-guided anesthesia for cerebello-pontine angle surgeries: A randomized clinical trial.

Background and Aims:The study was conceived to elucidate the effects of dexmedetomidine as an anesthetic adjunct to propofol (total intravenous anesthesia) on anesthetic dose reduction and anesthesia recovery parameters in cerebello-pontine angle (CPA) surgeries.Material and Methods:This prospective randomized study was conducted on 49 patients (25 with dexmedetomidine, 24 without). After standardized anesthetic induction, anesthesia was maintained using propofol (via target controlled infusion, titrated to maintain BIS between 40 and 60), fentanyl (0.5 μg/kg/hour) and either dexmedetomidine (0.5 μg/kg/hour) or a sham infusion. Neuromuscular blocking agents were excluded to allow cranial nerve EMG monitoring. Adverse hemodynamic events, recovery parameters (time to opening eyes, obeying commands, and extubation) and postoperative sedation score, shivering score, nausea, and vomiting score were recorded.Results:Propofol and fentanyl utilization (as total dose, adjusted for duration of surgery and body weight, and number of extra boluses) was significantly lower in the dexmedetomidine group. There was no difference in any of the recovery parameters between the two groups. Incidence of bradycardia was significantly higher with dexmedetomidine, while no difference was found for hypotension, hypertension, and tachycardia.Conclusion:Dexmedetomidine–fentanyl–propofol anesthesia compares favorably with fentanyl–propofol anesthesia during CPA neurosurgical procedures with regard to anesthesia recovery times, but with lower intraoperative opioid and hypnotic utilization rates.

Effect of bispectral index-guided anesthesia on consumption of anesthetics and early postoperative cognitive dysfunction after liver transplantation

The objective of this study was to summarize the incidence of postoperative cognitive dysfunction (POCD) after 7days following liver transplantation (LT), and to evaluate the effectiveness of bispectral index (BIS) guided anesthetic intervention in reducing POCD. Additional serum concentrations of S100β and neuron-specific enolase (NSE) were detected during surgery to determine whether they were reliable predictors of POCD.Patients who underwent LT at Beijing YouAn Hospital Affiliated to Capital University of Medical Science from January 2014 to December 2015 were enrolled. BIS monitor was needed during surgery. Patients who underwent LT without BIS monitoring during August 2012 to December 2014 served as historical controls. A battery of 5 neuropsychological tests were performed and scored preoperatively and 7days after surgery. POCD was diagnosed by the method of one standard deviation (SD). The blood samples of BIS group were collected at 5 time points: just before induction of general anesthesia (T0), 60 minutes after skin incision (T1), 30 minutes after the start of the anhepatic phase (T2), 15 minutes after reperfusion of the new liver (T3), and at 24 hours after surgery (T4).A total of 33 patients were included in BIS group, and 27 in the control group. Mean arterial pressure was different between 2 groups at 30 minutes after the start of the anhepatic phase (P = .032). The dose of propofol using at anhepatic phase 30 min and new liver 15 min was lower in the BIS group than control group (0.042 ± 0.021 vs. 0.069 ± 0.030, P < .001; 0.053 ± 0.022 vs. 0.072 ± 0.020, P = .001). Five patients were diagnosed as having POCD after 7 days in the BIS group and the incidence of POCD was 15.15%. In the control group, 9 patients had POCD and the incidence of POCD was 33.33%. The incidence of POCD between 2 groups had no statistical difference (P = .089). S100β increased at stage of anhepatic 30 minutes (T2) and new liver 15 minutes (T3) compared with the stage of before anesthesia (T0) (1.49 ± 0.66 vs. 0.72 ± 0.53, P < .001; 1.92 ± 0.78 vs. 0.72 ± 0.53, P < .001). NSE increased at stage of anhepatic 30 minutes (T2) and new liver 15 minutes (T3) compared with the stage of before anesthesia (T0) (5.80 ± 3.03 vs. 3.58 ± 3.24, P = .001; 10.04 ± 5.65 vs. 3.58 ± 3.24, P < .001). At 24 hours after surgery, S100β had no difference compared to one before anesthesia (1.0 ± 0.62 vs. 0.72 ± 0.53, P = .075), but NSE still remained high (5.19 ± 3.64 vs. 3.58 ± 3.24, P = .043). There were no significant differences in the serum concentrations of S100β between patients with and without POCD at 5 time points of operation (P > .05). But at 24 hours after surgery, NSE concentrations were still high of patients with POCD (8.14 ± 3.25 vs. 4.81 ± 3.50, P = .035).BIS-guided anesthesia can reduce consumption of propofol during anhepatic and new liver phase. Patients in BIS group seem to have a mild lower incidence of POCD compared to controls, but no statistical significant. The influence of BIS-guided anesthesia on POCD needs to be further confirmed by large-scale clinical study. S100β protein and NSE are well correlative with neural injury, but NSE is more suitable for assessment of incidence of postoperative cognitive deficits after surgery.

The impact of bispectral index-guided anesthesia on the incidence of postoperative delirium in elderly patients with chronic anemia

Objective Discuss the influence of BIS monitoring on the incidence of postoperative delirium(POD) in elderly patients with chronic anemia. Methods One hundred and eighty cases of elective surgery under general anesthesia were randomly divided into BIS monitoring group and control group(n=90), the control group using routine anesthesia, and BIS monitoring group maintaining the value of BIS between 40-60 during anesthesia. The hemodynamic indexes were monitored after entering the operation room(T0), after anesthesia(T1), immediate intubation(T2), 3 min after intubation(T3), cut the skin(T4), 1 h during operation(T5), the end of operation(T6). Observe the dose of propofol during anesthesia, surgery time, extubation time, recovery time and the occurrence of POD in patients. Results The overall incidence of BIS monitoring group delirium was 17.5%, lower than 31.2% in the control group(P< 0.05), the incidence of delirium on the first day of 13.3% was significantly lower than 28.9% in the control group(P<0.05), the incidence of 5.6% in the second day also lower than 14.4% in the control group(P<0.05), and duration of delirium was significantly lower than the control group (P<0.05). The extubation time[(26±8) min] and hospital stays[(11.5±2.3) d] of BIS monitoring group were significantly earlier than[(41 ± 12) min and (12.6 ± 4.4) d] control group, the difference was statistically significant(P<0.05). Conclusions BIS monitored anesthesia reduces the incidence of POD and reduces the duration of delirium in elderly patients with chronic anemia. Key words: Bispectral index; Elderly; Anemia; Postoperative delirium

Anesthesia awareness. Can midazolam attenuate or prevent memory consolidation on intraoperative awakening during general anesthesia without increasing the risk of postoperative delirium?

There are numerous reviews on anesthesia awareness (AA) and post-traumatic stress disorder. Some authors assert that the use of benzodiazepines (BZDs) should be limited to patients requiring lower anesthetic drugs dosages for cardiac and emergency surgery, and for multiple-trauma patients. This is in agreement, at least in part, with the recommendations of the American Society of Anesthesiologists (ASA) [1]. Indeed, according to the ASA guidelines, the decision to administer BZDs should be made on a case-by-case basis, whereby the use of BZDs has been limited because of the risk of postoperative confusion and cognitive problems, including postoperative delirium (PD). This is one of the most common complications after major surgery, affecting 10-70% of surgical patients of 60 years and older. There are a number of factors associated with PD, including hypoxia, hypercapnia, pain, stress, anxiety, fear, and psychotic and neurotic disorders, making it very difficult to determine the exact dose of midazolam - the BZD most used in anesthesia - that does not increase the risk of PD. Postoperative sedation using a midazolam drip (0.5-2 mg/h) results in delirium in 50% of the patients undergoing elective cardiac surgery.

Bispectral index-guided anesthesia on time to tracheal extubation after onpump cardiac surgery

Electroencephalographic-based cerebral monitors such as the bispectral index (BIS) have been used for titration of both inhalational and intravenous anesthetics during general anesthesia. Titration of anesthetics using these monitors may facilitate an earlier recovery from general anesthesia and less consumption of anesthetics. The primary aim of this study was to investigate whether BIS-guided anesthesia would reduce time to tracheal extubation when compared with minimum alveolar concentration (MAC)-guided anesthesia in patients undergoing onpump cardiac surgery.

Bispectral Index-Guided Anesthesia in Patients Undergoing Aortocoronary Bypass Grafting

Bispectral Index-Guided Anesthesia in Patients Undergoing Aortocoronary Bypass Grafting

Bispectral Index-Guided General Anesthesia in Combination with Thoracic Epidural Analgesia Reduces Recovery Time in Fast-Track Colon Surgery

Bispectral Index-Guided General Anesthesia in Combination with Thoracic Epidural Analgesia Reduces Recovery Time in Fast-Track Colon Surgery

Protocol for the BAG-RECALL clinical trial: a prospective, multi-center, randomized, controlled trial to determine whether a bispectral index-guided protocol is superior to an anesthesia gas-guided protocol in reducing intraoperative awareness with explicit recall in high risk surgical patients

BackgroundAwareness with explicit recall of intra-operative events is a rare and distressing complication that may lead to severe psychological symptoms. Candidate depth of anesthesia monitors have been developed, partly with the aim of preventing this complication. Despite conflicting results from clinical trials and the lack of incisive validation, such monitors have enjoyed widespread clinical adoption, in particular the bispectral index. The American Society of Anesthesiologists has called for adequately powered and rigorously designed clinical trials to determine whether the use of such monitors decreases the incidence of awareness in various settings. The aim of this study is to determine with increased precision whether incorporating the bispectral index into a structured general anesthesia protocol decreases the incidence of awareness with explicit recall among a subset of surgical patients at increased risk for awareness and scheduled to receive an inhalation gas-based general anesthetic.Methods/DesignBAG-RECALL is a multi-center, randomized, controlled clinical trial, in which 6,000 patients are being assigned to bispectral index-guided anesthesia (target range, 40 to 60) or end-tidal anesthetic gas-guided anesthesia (target range, 0.7 to 1.3 age-adjusted minimum alveolar concentration). Postoperatively, patients are being assessed for explicit recall at two intervals (0 to 72 hours, and 30 days after extubation). The primary outcome of the trial is awareness with explicit recall. Secondary outcomes include postoperative mortality, psychological symptoms, intensive care and hospital length of stay, average anesthetic gas administration, postoperative pain and nausea and vomiting, duration of stay in the recovery area, intra-operative dreaming, and postoperative delirium.DiscussionThis trial has been designed to complement two other clinical trials: B-Unaware and MACS (ClinicalTrials.gov numbers, NCT00281489 and NCT00689091). With the large patient numbers and complementary rigorous designs, it is envisaged that pre-specified meta-analyses will address some of the outstanding controversies and questions relating to processed electroencephalography monitoring.Trial registrationClinicalTrials.gov Identifier: NCT00682825

Sevoflurane Provides Better Recovery as Compared With Isoflurane in Children Undergoing Spinal Surgery

Rapid recovery is desirable in pediatric neurosurgical patients to obtain an early neurologic assessment. We compared the recovery characteristics of 2 commonly used anesthetic agents, sevoflurane and isoflurane, under bispectral index-guided anesthesia in children undergoing spinal surgery. Eighty children who underwent surgery for occult spinal dysraphism at the lumbar and sacral level were randomized to anesthesia with sevoflurane or isoflurane in oxygen and nitrous oxide. Anesthesia depth was guided by a bispectral index monitor kept between 40 and 60. In addition to time at emergence, extubation and discharge, recovery (modified Aldrete) score, and hemodynamics were compared. The 2 groups did not differ significantly with respect to demographics, duration of surgery and anesthesia, and intraoperative hemodynamic changes. Extubation (6.4+/-3.3 vs. 10.7+/-4.6) and emergence (7.8+/-3.4 vs. 12.8+/-5.6) times (minutes) were significantly shorter with sevoflurane (P<0.001). Time (minutes) to achieve full Aldrete (modified) scores was less with sevoflurane (13.9+/-5.3 vs. 20.3+/-6.5) than isoflurane (P<0.001). However, the time (minutes) to achieve discharge criteria from postanesthesia care unit (140.7+/-49.3 vs. 146+/-43.3) and first dose of postoperative analgesic (60+/-24.1 vs. 72+/-33.4) in addition to incidence of postoperative agitation were similar in both groups (P>0.05). Sevoflurane results in an earlier recovery and assessment of modified Aldrete score when compared with isoflurane.

Bispectral index-guided anaesthesia for intraoperative electrocorticographic analysis in epilepsy surgery: a prospectiveobservational study

Objective To explore a rational BIS range for adapting ECoG monitoring during the epilepsy urgery. Method With a prospective observational study after hospital ethics committee approval, 13 adult patients who underwent elective ECoG-guided anterior temporal corticeetomy consecutively were maintaining the BIS at variable values in the range of BIS > 60.BIS51～60,and BIS40～50 groups in all patients. Interictal epileptiform discharges (IEDs) and burst suppression rates (BSRs) admixed spikes were observed in different BIS groups, and the number of epileptiform spikes were compared by using a one-sided sign test;P values 60 IEDs had significant difference (P=0.03), BIS 40～50 verus BIS > 60 and BIS 51～60 BSRs also had statistically significant (P=0.00 and P=0.03), Conclusions (1) The frequency of single spikes or repetitive spike in the epileptogenic zone had increased tendency in BIS-guided general anaesthesia epilepsy surgery;(2)The BSRs admixed epileptiform activity such as spikes or sharp waves presented obviously when deepened the anaesthesia level, especially during BIS 40～50 condition;(3) If BIS monitoring general anesthesia epilepsy surgery is performing,we suggest to control the BIS in the range of 40～50 will benefit for studying the ECoG characteristics, and further,to facilitate localization of the epileptogenic zone for planning the tailored corticectomy;(4)We speculate that the anesthetic agents, particularly remifentanil could enhance epileptiform activity during intraoperative ECoG,whereas, the dose of propofol has significant correlation with the BIS monitoring. Key words: Epilepsy; Epilepsy surgery; Anaesthesia; Bispectral index; Electrocorticography

Bispectral index-guided anaesthesia for off-pump coronary artery bypass grafting

Bispectral index (BIS) monitoring may assist reduction in utilisation of anaesthetic agents during general surgical procedures. This study was designed to test whether the use of BIS monitoring reduces the anaesthetic requirements during off-pump coronary artery bypass grafting (CABG). This prospective - clinical trial was conducted on 40 adult patients undergoing elective off-pump CABG. Patients received either isoflurane or propofol anaesthesia. BIS monitoring, which guided the dose of anaesthetic, was carried out in 50 percent of the patients. The amount of anaesthetic agent (isoflurane or propofol) administered from the start of anaesthesia to the end of surgical procedure was calculated and were compared in four groups of patients - namely Group A (I-no BIS) received isoflurane; end tidal concentration was maintained at 1-1.2% in a low flow technique throughout the procedure, Group B (I-BIS) received isoflurane in a low flow technique; inspired concentration was dictated by BIS value maintained at 50; Group C (P-no BIS) received propofol at a dose range of 4-8 mg/kg/hr and in Group D(P-BIS) the propofol infusion rate was dictated by BIS value maintained at 50. The quantity of isoflurane was significantly less for Group B (I-BIS) as compared with Group A (I-no BIS) (37 +/- 4 vs. 24 +/- 4 ml; p< 0.05) and similarly the amount of propofol infused was significantly less in Group D (P-BIS) as compared with Group C (P-no BIS) (176 +/- 9 vs. 120 +/- 6 ml; p< 0.05). BIS guided anaesthesia reduces the anaesthetic agent required for the performance of off-pump CABG. This can be extrapolated in terms of saving agent and reduced cardiac depression during off-pump CABG.

Auditory-evoked potentials in bispectral index-guided anaesthesia for cardiac surgery

Background and objective: Midlatency auditory-evoked potentials, as measures of the anaesthetic state, were evaluated at similar levels of bispectral index in cardiac surgical patients maintained with either propofol or isoflurane anaesthesia. Methods: Twenty-four patients were randomly allocated to anaesthesia with propofol (n = 12) or isoflurane (n = 12). Bispectral index was maintained below 60 during surgery. Auditory-evoked potentials were collected before induction of anaesthesia, 10 min after intubation, 30 min after sternotomy, during cardiopulmonary bypass at the time of cross-clamping of the aorta and during stable mild hypothermia, after de-clamping of the aorta, and after the operation. Results: At the pre-determined time points, bispectral index values showed comparable depth of hypnosis in both groups. The latency of the Nb component of midlatency auditory-evoked potentials was significantly increased in the isoflurane group after intubation (P < 0.001) and that of both the Nb and the Pa components after sternotomy (P < 0.001) compared with the propofol group. No differences between the groups were detected with respect to haemodynamic variables. No patient reported recall of intraoperative events. Conclusion: After intubation and surgical stimulation, when bispectral index was at a constant level, there was a difference in the Nb and Pa components of the midlatency auditory-evoked potentials between the two anaesthetic regimens, indicating a distinction in the state of anaesthesia. Our results suggest that the parallel use of these two electrophysiological methods can show differences in the components of anaesthesia between various anaesthesia methods in cardiac surgical patients.

Bispectral index-guided desflurane and propofol anesthesia in ambulatory arthroscopy: comparison of recovery and discharge profiles

In this prospective, randomized study we compared the recovery profiles of bispectral index (BIS)-guided anesthesia regimens with desflurane or propofol in ambulatory arthroscopy. Fifty ASA I-II adult patients who underwent knee arthroscopy were randomized to receive desflurane (D) or propofol (P) infusion accompanied by remifentanil and nitrous oxide during maintenance, titrated to maintain a bispectral index value between 50 and 60. Initial awakening, fast-track eligibility, and home readiness as well as intraoperative hemodynamics, were compared. The groups did not differ with respect to demographics, duration of operation, or intraoperative vital signs. Although the times for initial awakening parameters were shorter in group D, the differences between the groups were not significant. The time needed for the White fast-track score to reach 12 was shorter in group P than group D (9 +/- 3.5 min vs 12.5 +/- 5.3 min). However, home readiness did not differ significantly between the groups. Desflurane is an alternative to propofol for BIS-guided ambulatory anesthesia. Using desflurane in combination with opioid analgesics blunted its rapid emergence characteristics, and the higher frequency of emetic symptoms with desflurane diminished the success of its fast-track eligibility.

Recovery from Bispectral Index-guided Anaesthesia in a Large Randomized Controlled Trial of Patients at High Risk of Awareness

Electroencephalographic monitors of anaesthetic depth are reported to assist anaesthetists in reducing recovery times. We explored the effect of bispectral index (BIS) monitoring on recovery times in a double-blind, randomized controlled trial of 2,463 patients at high risk of awareness. Patients were randomized to BIS-guided anaesthesia or routine care. In the BIS group, anaesthesia was adjusted to maintain a BIS value of 40-60 from the commencement of laryngoscopy to the start of wound closure, and 55-70 during wound closure. In the routine care group, anaesthesia was adjusted according to traditional clinical signs. In multivariate models, BIS monitoring, female gender, lower American Society of Anesthesiologists' physical status and shorter duration of anaesthesia predicted faster time to eye-opening after anaesthesia, and faster time to post-anaesthesia care unit discharge. BIS monitoring did not affect times to tracheal extubation among patients admitted to the intensive care unit. We conclude that BIS monitoring has statistically significant, but clinically modest, effects on recovery times in high risk surgical patients.

Bispectral index-guided administration of anaesthesia: comparison between remifentanil/propofol and remifentanil/isoflurane

Background and objective: The bispectral index of the electroencephalogram is a measure of the hypnotic component of anaesthesia and can be used to guide the administration of anaesthesia. This study compares bispectral index-guided anaesthesia with remifentanil and either propofol or isoflurane. Methods: Eighty consenting patients were randomly assigned to two groups. Following induction with propofol and remifentanil, anaesthesia was maintained with remifentanil/propofol or remifentanil/isoflurane. Remifentanil infusion rates were guided by haemodynamic responses - maintaining mean arterial pressure and heart rate within 20% of baseline. Propofol and isoflurane administration was guided using the bispectral index (45-60). Thirty minutes before the end of surgery, morphine was administered (0.15 mg kg−1 intravenously). Fifteen minutes before end of surgery, propofol and isoflurane were reduced (bispectral index 60-75). At the end of surgery, the anaesthetic agents were discontinued. Groups were compared for recovery, remifentanil doses and signs of inadequate anaesthesia using the χ2-test and ANOVA (P < 0.05). Results: The duration of surgery was longer in the propofol/remifentanil group (121 ± 53 versus 94 ± 40 min). Recovery data were not different between groups. The remifentanil infusion rate was significantly lower with additional isoflurane (0.18 ± 0.06 μg kg−1 min−1) than with additional propofol (0.31 ± 0.20 μg kg−1 min−1). The propofol infusion rate was 123 ± 48 μg kg−1 min−1; isoflurane concentration was 0.66 ± 0.13%. Conclusions: Bispectral index-guided anaesthesia with remifentanil plus propofol or isoflurane results in the absence of postoperative recall and a fast recovery with both drug combinations. In our patients, at comparable bispectral index-levels, haemodynamic control requires higher doses of remifentanil with propofol than with isoflurane.

Bispectral Index-Guided Anesthesia in Patients Undergoing Aortocoronary Bypass Grafting: Retracted

Lehmann, Andreas MD*; Karzau, Julia*; Boldt, Joachim MD*; Thaler, Elfi MD*; Lang, Johannes*; Isgro, Frank MD† Author Information