Use Of Bispectral Index Monitoring Research Articles

Intraoperative hypotension and perioperative outcomes.

Intraoperative hypotension is associated with adverse outcomes. Although a causal relationship is yet to be fully established, proactive management of vulnerable patients and use of bispectral index monitoring is recommended to avoid deep anaesthesia.

The Use of Bispectral Index Monitoring Does Not Change Intraoperative Exposure to Volatile Anesthetics in Children.

The exposure of infants and children to volatile anesthetics, such as sevoflurane, has been a topic of concern with respect to the potential risk for long term neurocognitive effects. The primary objective of this study was to determine whether the perioperative utilization of Bispectral Index (BIS) monitoring alters the sevoflurane delivery and exposure to children. This is a prospective randomized trial of two groups of healthy ambulatory day surgery patients (2 to 12 years). The patients in both groups had the BIS applied soon after the induction of general anesthesia, but only the anesthesiologists in the group randomized to BIS visible were able to see the BIS values. All of the patients received general anesthesia with sevoflurane. This study found no difference in the overall exposure to sevoflurane between both groups (mean end-tidal sevoflurane level of 1.8 in both groups, P = 084). The duration of time in the recovery room, the time to meet discharge criteria, the Pediatric Agitation Emergence Delirium (PAED) scores and the Face, Legs, Activity, Cry, Consolability (FLACC) scores were not statistically different between the groups. The application and utilization of intraoperative BIS monitoring does not alter the sevoflurane administration nor the discharge readiness nor the recovery profile in healthy ambulatory children.

Use of bispectral index monitoring to predict the outcome of patients with posterior reversible encephalopathy syndrome: Two case reports

Posterior reversible encephalopathy syndrome (PRES) is a reversible neurologic disorder characterized by a variety of symptoms such as seizures, headache, vomiting, altered mental status, and visual disturbances. Bispectral index (BIS) monitor is a kind of electroencephalography and is widely used in anesthesia depth surveillance. In intensive care units, BIS has been used to survey sedation and predict prognosis of coma patients. Here, we report two cases diagnosed radiologically with PRES that had persistent consciousness disturbance resulted from severe life-threatening complications. In our patients, they progressed with different BIS values and different outcomes. We advise that BIS should be used in intensive care as an adjunctive monitor when patients' consciousness status could not be predicted.

Practice patterns in the intraoperative use of bispectral index monitoring

Assessing the depth of anesthesia and reducing intraoperative awareness has become a focus of much technology development and research in the field of anesthesia. Bispectral index (BIS) is the most widely utilized technology that uses electroencephalogram to provide a measurement of anesthetic depth. There are no definitive guidelines on when BIS should be used. Our aim was to assess actual patterns of intraoperative use of BIS by anesthesia professionals. We retrospectively collected intraoperative data on 55,210 surgical cases at a tertiary care hospital. Variables collected included: age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA) physical status, anesthesia provider type and level of training, use of inhalational anesthetics versus total intravenous anesthesia (TIVA), utilization of nitrous oxide, utilization of non-depolarizing neuromuscular blockade, emergency status of surgery, airway type, case duration, and surgical subspecialty. A univariate logistic regression model was fitted. Subsequently, a multivariate logistic regression model was applied. Covariates utilized for the model included age, anesthesia provider level, and length of case. Factors associated with BIS use included increased age, greater ASA physical status, extremes of BMI, use of TIVA, use of a long-acting paralytic agent, use of an endotracheal tube (ETT), emergency surgery, increasing length of case, and certain surgical services. BIS use was associated with previously documented risk factors for intraoperative awareness. These factors are also indicators of case complexity, which may be a major factor among providers deciding when to apply BIS monitoring in the operating room.

Intra-operative use of Bispectral Index Monitoring and Time to Extubation and Patients Length of Stay after Cardio Pulmonary Bypass Surgery, at An-Najah National University Hospital / Nablus /Palestine. A Randomized Control Study

Background: The primary goal of cardiac surgery is not just a minimally acceptable outcome where the patient survives without life threatening complications, but a healthy productive long term survivor. There is no universally accepted technique for anesthesia management during cardiac surgery,Anesthetic protocols in cardiac surgery are investigated and analyzed in terms of their effect on post-operative mortality and incidence of myocardial infarction following cardiac surgery, needs for inotropic support, time to extubation, time on mechanical ventilation, and hospital length of stay. Fast–track tracheal extubation (within 6 hours after the surgery) after cardiac surgery has become a methods which is believed to facilitate this must be validated. One of these methods, is the use of intra-operative monitoring Modalities, such as (BIS) which is a value derived from electroencephalogram, and had been used as a measure of anesthesia effect. We performed this study in An-najah National University Hospital / Palestine to investigate the role of BIS monitoring on time to extubate and CCU length of stay after cardiopulmonary bypass surgery. Methods: In a randomized control study we used the bispectral index monitoring during cardiopulmonary bypass between 40-50 and in the CCU between 60-70 until extubation. 100 patients between the age of 30 and 75 years undergoing elective cardiopulmonary bypass surgery and patients undergoing elective valve replacement or repair, from 01/10/2015 to 01/04/2016 were assigned for this study, randomized to 50 patients each in the BIS group and the conventional group. Results: Extubation time data were available for 100 patients. The median time to extubate (320) minutes in the BIS group and (365) minutes in conventional group. The median CCU length of stay (24.1) hours in BIS group and (24.3) hours in conventional group. Regarding hospital length of stay, there was no difference in between the two groups, with median time of (5 days) in both groups. Conclusions: Data from this study suggested that the use of the BIS monitor during cardio pulmonary bypass does not confer an advantage in reducing time to extubation, CCU length of stay, or overall hospital length of stay.

An audit of the intraoperative use of bispectral index monitoring at a specialist cardiothoracic hospital

An audit of the intraoperative use of bispectral index monitoring at a specialist cardiothoracic hospital

Use of bispectral index monitoring for a patient with hepatic encephalopathy requiring living donor liver transplantation: a case report

We report the use of perioperative bispectral index (BIS) monitoring in a patient who underwent living donor liver transplantation (LDLT). Hepatic encephalopathy featuring extreme excitement developed in a 42-year-old male and was diagnosed as acute hepatitis. Sedation with continuous infusion of midazolam was necessary. BIS value gradually decreased and reached 0 17h after commencement of continuous infusion of midazolam. Midazolam infusion was stopped but BIS value remained 0. Brain CT scan revealed an almost normal image. Multi-lead electroencephalogram was recorded revealing almost no electrical activity. Administration of flumazenil did not improve his consciousness and BIS value. Adequate spontaneous respiration was maintained and the possibility of brain death was excluded. LDLT was performed on the 5th ICU day. BIS value remained 0 throughout surgery. BIS value suddenly increased 2h after surgery and reached 60 11h after surgery. It became possible to communicate with the patient and his trachea was extubated on the 4th postoperative day. We believe that, with BIS, we were able to follow preoperative exacerbation of the "pathological" process of hepatic encephalopathy, and predict postoperative emergence from general anesthesia, suggesting normal graft function.

Nitrous Oxide and Evidence-based Medicine: Here We Go Again

Nitrous Oxide and Evidence-based Medicine: Here We Go Again

The use of bispectral index monitoring in education – a tool to improve nurse‐anaesthetists practice

This paper is a report of a study to investigate whether monitoring depth of anaesthesia by bispectral index would reduce recovery time and consumption of anaesthetic drugs in anaesthetics performed by student nurse-anaesthetists. It is difficult to assess the depth of anaesthesia clinically. Studies have shown that experienced anaesthetists can titrate anaesthetics more accurately when using bispectral index monitors. It is not known if student nurse-anaesthetists can benefit from their use in a similar way. A multicentre study involving four hospitals was carried out during a 13-month period in 2003 and 2004. In total 25 nurses participated, each contributing with two procedures: one with monitoring and one without. The nurses had at least 10 months of experience in conducting anaesthesia and all had a theoretical introduction and a test session to become familiar with the equipment. The sequence was randomized and the observer was blinded to whether a monitor was used. Fifty patients were anaesthetized with propofol and fentanyl. Recovery time, consumption of anaesthetic drugs, and patient satisfaction were measured in both groups. Recovery time was 11 minutes in the monitor group (range: 2-53 minutes) and 15 minutes in the control group, (range: 3-60 minutes). P = 0.26. There were no statistically significant differences in consumption of anaesthetic drugs or patient satisfaction in the two groups. It was not possible to demonstrate a statistically significant reduction in recovery time or consumption of anaesthetic drugs when using bispectral index monitoring during training of student nurse-anaesthetists.

Anaesthetic management of thoracopagus twins with complex cyanotic heart disease for cardiac assessment: special considerations related to ventilation and cross-circulation

We describe the anaesthetic management of a pair of thoracopagus twins of 14 months of age undergoing complex cardiac evaluation. Synchronous ventilation of the twins, needed for the ECG-gated magnetic resonance imaging-angiography, was achieved through a Carlens (Y) adaptor during procedures and transport. The complex logistical implications are obvious. We also describe the first use of bispectral index monitor for detection of cross-circulation in conjoint twins.

Interventional neurophysiologic monitoring

Intraoperative neurophysiologic monitoring provides useful information on the functional status of the nervous system. This review focuses on recently published data concerning the impact of monitoring on patient outcome. There is level I evidence to support the use of bispectral index monitoring to prevent awareness during anesthesia in high-risk patients. A number of randomized trials have shown that monitoring-guided anesthesia using the bispectral index or other devices will expedite recovery and improve perioperative drug utilization. There are also preliminary reports suggesting that anesthesia dictated by bispectral index monitoring may alter long-term outcome and reduce mortality. In surgical procedures, however, it is less clear whether neurophysiologic monitoring will improve patient outcome. Currently, the majority of data are derived from respective case series. Nonetheless, monitoring with somatosensory evoked potential has been shown to reduce postoperative neurologic deficits after spinal surgery. There is also evidence to suggest that electromyography and motor evoked potential are essential complements to somatosensory evoked potential for monitoring of spinal cord surgery. Brain monitoring facilitates anesthetic drug administration. An increasing number of neurosurgical procedures will require some form of intraoperative neurophysiologic monitoring to achieve higher degrees of safety and accuracy. In many instances, the data derived from monitoring will guide and influence surgical decisions. In this context, neurophysiologic monitoring should be regarded as interventional.

Use of Bispectral Index Monitor (BIS) to Follow Depth of Sedation in Patients Undergoing Colonoscopy with Propofol Sedation

Background: Sedation for gastrointestinal endoscopy is guided by patient responses to noxious stimuli. Differences in patient response to propofol occasionally result in instability due to oversedation. BIS is used to monitor depth of anesthesia by recording electroencephalographic data from the frontal cortex of the brain, which is predictive for intraoperative awareness. The objective of this study is to determine the ability of BIS to monitor sedation during colonoscopy. Materials & Methods: 45 patients were premedicated with midazolam (1-2 mg) and sedated with propofol. BIS readings were recorded at baseline, start, end, and minimum value. The same endoscopist performed all procedures. The endoscopist and an observer evaluated adequacy of sedation. Patients were asked to follow a simple command at the end of the procedure and again five minutes later. Any adverse outcomes were documented. Results: A statistically significant difference in the BIS score was noted between patients able to follow a command compared to those that were not at the end of each procedure (p<0.001). Patients with BIS values 30-60 at the end of the procedure took greater than 5 minutes to wake up, while those with values 58-90 woke up within one minute of the end of the procedure. BIS scores less than 70 were seen in patients requiring longer wake up times. Length of stay post-procedure in the endoscopy suite was longer in patients with longer wake up times. Predicted probability curves demonstrate that BIS values of at least 70 correlates with a 90% likelihood that the patient will be awake within 5 minutes of procedure completion with no procedural recall. There was a significant difference in BIS scores between baseline and all measured data points obtained during colonoscopy (p<0.001). Mean BIS values for baseline, procedure start, minimum, and end of procedure were 96, 65, 37, and 65 respectively. There were no adverse outcomes recorded. Conclusions: The BIS monitor may be used as part of a monitoring system during colonoscopy. Low BIS values correlate with deeper sedation and longer recovery times. BIS values between 54 and 76 appear optimal to avoid adverse events as well as over and under sedation. Use of the BIS monitor may allow improved titration of medication to shorten procedural recovery time, decrease procedure related costs and complications.

Cost-benefit analysis of use of bispectral index monitoring during major orthopaedic surgery

Cost-benefit analysis of use of bispectral index monitoring during major orthopaedic surgery

Intrathecal morphine for coronary artery bypass graft surgery revisited

We read with great interest Chaney et al's1Chaney MA Nikolov MP Blakeman BP Bakhos M Intrathecal morphine for coronary artery bypass graft procedure and early extubation revisited.J Cardiothorac Vasc Anesth. 1999; 13: 574-578Abstract Full Text PDF PubMed Scopus (48) Google Scholar study regarding intrathecal morphine in coronary artery bypass graft (CABG) surgery patients and early extubation. Dr. Chaney and colleagues are to be congratulated for completing this rigorous, placebo-controlled, double-blind study. It is possible, however, that the study design, although accomplishing methodologic goals, biases the clinical results. In the current study, as in Chaney's previous study,2Chaney MA Furry PA Fluder EM Slogoff S Intrathecal morphine for coronary artery bypass grafting and early extubation.Anesth Analg. 1997; 84: 241-248PubMed Google Scholar the use of intrathecal narcotics is an adjunct to the primary, balanced anesthetic technique. It is not surprising that his use of intrathecal morphine was no different from placebo because it simply supplements what is an adequate anesthetic for fast-track cardiac surgery. Similarly, the use of intrathecal morphine in this situation could be expected to increase sedation and prolong time to extubation in certain patients. Fentanyl, 10 μg/kg, and midazolam, 0.2 mg/kg, are quite sufficient, when combined with volatile anesthetics and vasoactive agents, to provide perioperative analgesia and sedation in patients undergoing cardiopulmonary bypass (CPB). In private practice, many clinicians use significantly smaller doses of opioids and benzodiazepines to achieve rapid extubation (J Turner: personal communication). Intraoperative analgesia is further accomplished by use of volatile agents, whereas patient-controlled analgesia with morphine adequately addresses postoperative pain management needs. It has been our clinical impression that patients undergoing CPB have smaller postoperative analgesia requirements than patients undergoing non-CPB sternotomy. Although this situation has not been investigated, we speculate that cerebral edema and inflammation associated with even routine, uneventful bypass3Taylor KM Central nervous system effects of cardiopulmonary bypass.Ann Thorac Surg. 1998; 66: S20-S24Abstract Full Text Full Text PDF PubMed Scopus (95) Google Scholar may alter the sensorium sufficiently to account for this decrease. An ongoing study at this institution seems to indicate that intrathecal morphine at a dose of 5 μg/kg is adequate for postoperative pain control. No intravenous opioid or benzodiazepine is used in the preoperative and intraoperative periods. The intrathecal mor-phine is the sole fixed analgesic, rather than a supplement. Intraoperative amnesia and analgesia are accomplished with volatile anesthetics, whereas stress and hemodynamics are managed by other vasoactive agents, such as β-blockers and vasodilators. Aprotinin is also used liberally in high doses for its anti-inflammatory effects. Use of bispectral index monitoring throughout the intraoperative period facilitates this technique further by guiding clinicians in the use of volatile agents for hypnosis. Of the 10 patients we have studied so far, all have been easily extubated within the first hour of surgery, several immediately in the operating room during dressing application. So far, we have not experienced complications, such as reintubation or hypoxia and hypercarbia, and the patients have experienced a significantly shorter intensive care unit stay. We hope to submit our data for peer review in the near future. In conclusion, we believe that narcotics and benzodiazepines used in the perioperative period significantly affect the clinical short-term outcome after the use of intrathecal morphine for CABG surgery. It is possible that severely limiting or elim-inating parenteral use of these agents may allow clinicians to realize the combined benefits of early extubation and satisfac-tory pain control offered by intrathecal morphine. An additional variable to consider is decreased requirement for pain medica-tion after CPB, which may be accomplished by smaller doses of intrathecal morphine than those used by Chaney. Although our data have yet to undergo peer review, other studies have also shown the effectiveness of intrathecal morphine at significantly smaller doses.4Taylor A Healy M McCarroll M Moriarty DC Intrathecal morphine: One year's experience in cardiac surgical patients.J Cardiothorac Vasc Anesth. 1996; 10: 225-228Abstract Full Text PDF PubMed Scopus (30) Google Scholar, 5Swenson JD Hullander RM Wingler K Leivers D Early extubation after cardiac surgery using combined intrathecal sufentanil and morphine.J Cardiothorac Vasc Anesth. 1994; 8: 509-514Abstract Full Text PDF PubMed Scopus (44) Google Scholar, 6Tobias JD Deshpande JK Wetzel RC et al.Postoperative analgesia: Use of intrathecal morphine in children.Clin Pediatr. 1990; 29: 44-48Crossref PubMed Scopus (36) Google Scholar

Women Emerge From General Anesthesia with Propofol/Alfentanil/Nitrous Oxide Faster Than Men

Background: Recovery from general anesthesia is governed by pharmacodynamic and pharmacokinetic factors. Gender has not previously been recognized as a factor influencing the time to emergence from general anesthesia. Methods: This multicenter study was originally designed to measure the effects of the bispectral index on intraoperative anesthetic management and patient recovery. We compared the wake-up and recovery times of 274 adults after propofol/ alfentanil/nitrous oxide anesthesia. Patients were randomly assigned to have the titration of propofol performed with or without the use of bispectral index monitoring. Specific guidelines were given for the titration of drugs. The aim in all cases was to provide a safe anesthetic with the fastest possible recovery. Results: There was a significant reduction in propofol dose, time to eye opening, and response to verbal command when the anesthetic was titrated using the bispectral index. Unexpectedly, gender proved to be a highly significant independent predictor for recovery time. Women woke significantly faster than men: the time from end of anesthesia to eye opening was 7.05 versus 11.22 min, P < 0.05, and response to verbal command was 8.12 versus 11.67 min, P < 0.05. These differences were significant at all four study sites and in each treatment group. Men consistently had prolonged recovery times compared to women, P < 0.001. There was no difference in the dose of anesthetic used between gender. Conclusions: Gender appears to be an important variable in recovery from general anesthesia. These findings may explain the increased reported incidence of awareness in women (three times more frequent) and support the need to include gender as a variable in pharmacokinetic and pharmacodynamic studies of anesthetic drugs.