BIS-guided Anesthesia Research Articles

Effect of BIS-guided anesthesia on emergence delirium following general anesthesia in children: A prospective randomized controlled trial

ObjectiveEmergence delirium (ED) is a postoperative complication in pediatric anesthesia characterized by a perception and psychomotor disorder, with a negative impact on postoperative recovery. As the use of inhalation anesthesia is associated with a higher incidence of ED, we investigated whether titrating the depth of general anesthesia with BIS monitor can reduce the incidence of ED. DesignRandomized, prospective, and double-blind. SettingPatients undergoing endoscopic adenoidectomy under general anesthesia according to a uniform protocol. PatientsA total of 163 patients of both sexes aged 3–8 years were enrolled over 18 months. InterventionsImmediately after the induction of general anesthesia, a bispectral index (BIS) electrode was placed on the patient’s forehead. In the study group, the depth of general anesthesia was monitored with the aim of achieving BIS values of 40–60. In the control group, the dose of sevoflurane was determined by the anaesthesiologist based on MAC (minimum alveolar concentration) and the end-tidal concentration. MeasurementsThe primary objective was to compare the occurrence of ED during the PACU (post-anesthesia care unit) stay in both arms of the study. The secondary objective was to determine the PAED score at 10 and 30 min in the PACU and the need for rescue treatment of ED. Main results86 children were randomized in the intervention group and 77 children in the control group. During the entire PACU stay, 23.3% (38/163) of patients developed ED with PAED score >10: 35.1% (27/77) in the control group and 12.8% (11/86) in the intervention group (p = 0.001). Lower PAED scores were also found in the intervention group at 10 (p < 0.001) and 30 (p < 0.001) minutes compared to the control group. The need for rescue treatment did not differ between groups (p = 0.067). ConclusionIndividualization of the depth of general anesthesia with BIS monitoring is an effective method of preventing ED in children. Clinical trial registrationNCT04466579.

Evaluating the role of Smartpilot® view assisted target-controlled infusion anesthesia during intracranial mass surgery: A comparative retrospective study with bispectral index-guided standard anesthesia

Background/Aim: Neuroanesthesia necessitates the control of both systemic and cerebral hemodynamics, the prevention of intracranial pressure increase, knowledge of anesthetics’ cerebral effects, and early neurological recovery. The titration of anesthetics becomes crucial to optimize the appropriate level of anesthesia required for surgery while reducing postoperative neurological consequences. Smartpilot® View (SPV) is a new decision support system that uses pharmacologic models to optimize anesthetic depth and improve patient outcomes. The goal of this study was to compare the effectiveness of SPV with standard BIS-guided anesthesia administration in terms of intraoperative hemodynamic stabilization, anesthetic consumption, and postoperative recovery times during intracranial mass surgery. Methods: Following ethics committee approval, the records of the patients who underwent elective supratentorial craniotomy between November 15, 2017 and March 15, 2018 were reviewed retrospectively. The demographics of the patients, anesthesia and surgery times, eye opening and extubation times, time to reach an Aldrete score of 9 and anesthetic consumptions were compared between those who were monitored with SPV in addition to BIS (SPV Group) and those who were monitored with solely BIS for standard anesthetic follow-up (BIS Group). Results: A total of 139 subjects were analyzed (SPV (n=71), BIS (n=68)). Hemodynamic responses to induction and intubation were more pronounced in the BIS group (P<0.05). Time until eye opening and extubation were 3.6 (2.4) versus 6.06 (1.63) minutes and 5.76 (1.3) versus 9.16 (1.0) minutes in the SPV and BIS groups (P<0.001). In the SPV Group, it took much less time to achieve an Aldrete score of 9 or above (P<0.001). Total consumed amount of both propofol and remifentanil were significantly lower in the SPV group (P<0.001). Conclusion: Use of SPV compared to BIS-guided routine anesthesia follow-up improved titration and consumption of anesthetic drugs, thereby facilitating the early recovery process in patients who underwent intracranial mass surgery.

\u201cA real-world evidence\u201d in reduction of volatile anesthetics by BIS-guided anesthesia

Many well-controlled clinical studies have shown that BIS-guided anesthesia could prevent intraoperative awareness and improve postoperative morbidity and mortality, by optimizing the amount of volatile anesthetics administered to patients. However, we questioned if the previously reported advantages of BIS-guided anesthesia in controlled studies would still apply in real-world settings. This retrospective study based on real-world settings clarified the role of BIS-guided anesthesia in reducing anesthetic consumption. We obtained anesthesia records from an electronic database of a medical center in southern Taiwan. A total of 6,713 cases were enrolled, where 1,324 cases receiving sevoflurane underwent BIS-guided anesthesia and 378 received desflurane; further, 3,819 receiving sevoflurane underwent standard anesthesia practice and 1,192 cases received desflurane. The median (25–75% interquartile values) of the average hourly consumption of sevoflurane or desflurane decreased significantly under BIS-guided anesthesia [10.5 (8.7–13.0) mL/h and 17.4 (13.7–21.1) mL/h, respectively] compared to that under standard anesthesia practice [11.4 (9.0–14.5) mL/h, and 20.2 (15.8–25.0), mL/h, respectively]. Furthermore, the average hourly consumption of these two volatile anesthetics varied inversely with age and anesthesia time in both groups. A significant reduction was found in the hourly consumption of volatile anesthetics in patients under BIS-guided anesthesia compared to standard anesthesia practice in different age groups or different anesthesia time. We concluded that BIS-guided anesthesia could reduce consumption of volatile anesthetics in real-world settings as well.

Comparison of End-Tidal Anesthetic Gas Concentration versus Bispectral Index-Guided Protocol as Directing Tool on Time to Tracheal Extubation for Sevoflurane-Based General Anesthesia.

Background:Modalities for titrating anesthetic drug-like bispectral index (BIS) and end-tidal anesthetic gas (ETAG) concentration in predicting early extubation had been studied with old anesthetic agents such as isoflurane.Aim:The aim of this study is to compare the effect of ETAG concentration versus BIS-guided protocol as directing tool on time to tracheal extubation for sevoflurane-based general anesthesia.Materials and Methods:This prospective, randomized, double-blind trial studied sixty patients with American Society of Anesthesiologists physical status classes I and II who received sevoflurane-based general anesthesia and were allocated to either BIS–guided anesthesia group (n = 30) or ETAG–guided anesthesia group (n = 30). Time to tracheal extubation was measured. BIS value was kept between 40 and 60 in BIS group, whereas minimum alveolar concentration value was kept between 0.7 and 1.3 in ETAG group. The two groups were compared using Student's t-test, and P < 0.05 was considered statistically significant. The statistical analysis was performed using the open source “R” programming language.Results:Mean time to tracheal extubation was significantly shorter in BIS group (308.77 ± 20.48 s) as compared to ETAG group (377.90 ± 25.06 s) (P < 0.001). The sevoflurane concentration used was also significantly less in group BIS than group ETAG at multiple time intervals (P = 0.001).Conclusion:Prediction of extubation was significantly early with BIS monitoring as compared to ETAG monitoring in sevoflurane-based general anesthesia.

BIS index monitoring and perioperative neurocognitive disorders in older adults: a systematic review and meta-analysis.

Perioperative neurocognitive disorders (PND) are common in elderly patients after surgery. It has been reported that BIS-guided anesthesia potentially influenced the occurrence of PND. Therefore, we conducted this systematic review and meta-analysis to explore the associations between bispectral index (BIS) monitoring and PND. Two researchers independently searched for relevant randomized controlled trials (RCTs) in PubMed, EMBASE, and the Cochrane Library (CENTRAL) using keywords related to the BIS and PND from inception to April 22, 2019. Odds ratios (OR) with 95% CI were calculated using a random effects model. Nine RCTs involving 4023 participants aged 60years or older were included into this meta-analysis. BIS-guided anesthesia was not associated with lower incidence of POD (random effects; OR: 0.69; 95% CI 0.48, 1.01), delayed neurocognitive recovery (DNR) at 1day, 7days (random effects; OR: 0.14; 95% CI 0.02, 1.23; random effects; OR: 0.97; 95% CI 0.57, 1.63), and postoperative neurocognitive disorder (NCD) at 90days and 1year after surgery in older adults (random effects; OR:0.72; 95% CI 0.52, 1.00; random effects; OR: 0.26; 95% CI 0.03, 2.47). No definite evidence demonstrated that BIS-guided anesthesia decreased the incidence of POD, DNR and postoperative NCD in older patients. More homogeneous RCTs assessing the efficacy of BIS monitoring on reducing the occurrence of these perioperative cognitive disorders are needed.

Effect of bispectral index monitoring on postoperative delirium in elderly patients with moderate or severe hypertension undergoing total knee arthroplasty surgery

Objective To investigate the effect of BIS-guided intravenous anesthesia on postoperative delirium (POD) in elderly patients with moderate or severe hypertension undergoing total knee arthroplasty surgery. Methods Eighty patients with moderate or severe hypertension, aged 63-80 years old, ASA Ⅱ or Ⅲ, NYHA Ⅰor Ⅱ, with preoperative Mini-Mental State Examination (MMSE) score≥23 scheduled for total knee arthroplasty surgery were enrolled in this study. The patients were randomly assigned to two groups with 40 patients per group: experience anesthesia group (group E) and BIS monitoring group (group B). The group B adjusted the depth of anesthesia according to intraoperative BIS value while experience anesthesia group anesthesia was adjusted according to traditional clinical signs and hemodynamic parameters. The hemodynamic parameters were recorded at time before anesthesia induction (T0), 3 min after induction (T1), at time before using tourniquet (T2), 30 min after tourniquet use (T3), before tourniquet release(T4) and after tourniquet release (T5). Observing the respiratory recovery time, eye opening time, extubation time, PACU residence time, the dosage of propofol, the dosage of vasoactive agent and the anesthesia related complication. POD was assessed within 3 d after operation using the confusion assessment method (CAM). Results The SBP at the time of T1, T2 in group E were (112±9) mmHg (1 mmHg=0.133 kPa) and (103±7) mmHg while those values in group B were (119±11) mmHg and (108±9) mmHg respectively. The DBP at the time of T1 in group E was (66±7) mmHg while value in group B was (72±10) mmHg. Compared with group E, the SBP at the time of T1, T2 and DBP at the time of T1 in group B were higher than those values in group E (all P<0.05). The dosage of propofol in group B [(322±49) mg] was lower than the dosage of group E[(366±52) mg]. The time of respiratory recovery [(4.3±1.5) min], time of eye opening [(5.7±1.4) min], extubation time [(10.5±2.5) min] and PACU residence time [(32±5) min] in group B were shorter than those values in group E[(5.6±2.1), (7.4±2.1), (12.1±2.5), (35±6) min]. Moreover, the overall incidence of POD in group B (20.0%) was significantly lower than that of group E (45.0%) (P<0.05) . Conclusions BIS monitoring reduces the amount of anesthetics used in elderly patients with moderate or severe hypertension undergoing total knee arthroplasty surgery. It leads to less incidence of POD three days after operation. Key words: Bispectral index; Depth of anesthesia; Aged; Hypertension; Total knee arthroplasty; Postoperative delirium

The Clinical Effectiveness of the Bispectral Index (BIS) To Reduce the Risk of Awareness for Elective Surgical Patients Undergoing General Anesthesia: A Prospective, Randomized, Double-Blind, Controlled Trial

The Clinical Effectiveness of the Bispectral Index (BIS) To Reduce the Risk of Awareness for Elective Surgical Patients Undergoing General Anesthesia: A Prospective, Randomized, Double-Blind, Controlled Trial

Adaptive pharmacokinetic and pharmacodynamic modelling to predict propofol effect using BIS-guided anesthesia

Background and objectivePropofol is widely used for hypnosis induction and maintenance of general anesthesia. Its effect can be assessed using the bispectral index (BIS). Many automatic infusion systems are based in pharmacokinetics (PK) and pharmacodynamics (PD) models to predict the response of the patient to the drug. However, all these models do not take into account intra and inter-patient variability. An adjusted intraoperative drug administration allows faster recovery and provides post-operative side-effect mitigation MethodsBIS evolution and surgery-recorded propofol infusion data of a group of 60 adult patients (30 males/30 females) with ASA I/II physical status were used to test a real time PK/PD compartmental model. This new algorithm tunes three model parameters (ce50, γ and ke0), minimizing a performance function online. ResultsThe error in the BIS signal predicted by the real time PK/PD model was smaller than the error measured with fixed parameter equations. This model shows that ce50, γ and ke0 change with time and patients, given a mean (95% confidence interval) of 3.89 (3.52–4.26)mg/l, 4.63 (4.13–5.13) and 0.36 (0.31–0.4)min−1, respectively. ConclusionsThe real time PK/PD model proposed provides a closer description of the patient real state at each sample time. This allows for greater control of the drug infusion, and thus the quantity of drug administered can be titrated to achieve the desired effect for the desired duration, and reduce unnecessary waste or post-operative effects.

Effect of bispectral index versus end-tidal anesthetic gas concentration-guided protocol on time to tracheal extubation for halothane-based general anesthesia.

Background and Aims:Early extubation is a desirable goal after general anesthesia. Very few studies have compared the effect of bispectral index (BIS) monitoring versus standard end-tidal anesthetic gas (ETAG) concentration monitoring on tracheal extubation time for halothane-based anesthesia. The aim of this study was to compare the effect of BIS versus ETAG-guided anesthesia on time to tracheal extubation for halothane-based anesthesia in general surgical setting.Methods:This was a randomized, controlled double-blind study. Sixty patients with the American Society of Anesthesiologists physical status Class 1 or 2, receiving halothane-based general anesthesia were randomized to BIS-guided (n = 30) and ETAG-guided anesthesia (n = 30). Time to tracheal extubation was measured. In BIS group, BIS value was kept between 40 and 60 while in ETAG group; ETAG value was kept between 0.7 and 1.3 minimum alveolar concentration. The two groups were compared using Student's t-test, and P < 0.05 was considered statistically significant. Data were processed and analyzed using SPSS version 17 software.Results:Mean time to tracheal extubation was significantly longer in BIS group (9.63 ± 3.02 min) as compared to ETAG group (5.29 ± 1.51 min), mean difference 4.34 min with 95% confidence interval (3.106, 5.982) (P < 0.05).Conclusion:In our study, the extubation time was significantly longer in BIS-guided anesthesia as compared to ETAG-guided anesthesia. ETAG monitoring promotes earlier extubation of patients as compared to BIS monitoring during halothane anesthesia.

Hemodynamic changes and stress response during BIS-guided TCI anesthesia with propofol-fentanyl in laparoscopic versus open cholecystectomy

BackgroundLaparoscopic surgery produces measurable effects on cardio-circulatory, respiratory and metabolic systems. Total intravenous anesthesia with propofol using target-controlled infusion technique guided by Bispectral Index monitoring ensures an optimum level of anesthesia. This study was designed to evaluate the hemodynamic changes with the use of BIS-guided TCI with propofol-fentanyl during either laparoscopic or open cholecystectomy.MethodsTwenty-four ASA class I-II patients, scheduled for cholecystectomy under general anesthesia using BIS-guided TIVA with propofol-fentanyl delivered by TCI pump, were divided surgically into laparoscopic surgery group (LS group, n = 12) and open surgery group (OS group, n = 12). Hemodynamic data as well as stress hormones were measured at various time intervals.ResultsWithin LS, there was rise of both cardiac output after abdominal insufflation (p < 0.05) and stroke volume after end of surgery (p < 0.05). Blood pressure decreased in the two groups after insufflation in LS and skin incision in OS (p < 0.01) as well as after 15 min (p < 0.05 & p < 0.01 respectively). LS showed decrease in SVR starting from insufflation till end of surgery, while OS showed this decrease only with skin incision. Heart rate decreased 15 min after surgical incision till end of surgery in OS while LS showed decrease only after end of surgery. Only in OS, norepinephrine & epinephrine levels showed significant rises throughout the period of study (p < 0.001). Cortisol level was elevated after 30 min in LS while OS showed a rise after the end of surgery (p < 0.001). ACTH levels increased in OS (p < 0.001). There was positive correlation between CO and epinephrine, norepinephrine and ACTH in OS.ConclusionBIS-guided TCI anesthesia with propofol-fentanyl offers a good and safe anesthesia technique for patients undergoing either laparoscopic or open cholecystectomy. The hemodynamic stability guided by esophageal Doppler monitor makes it a very appealing choice.

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.

Comparative study of implicit memory during bispectral index guided total intravenous anesthesia versus sevoflurane inhalation anesthesia

BackgroundSeveral studies that investigate the implicit memory under general anesthesia revealed conflicting results. Limitations may be due to failure to control depth of anesthesia. This prospective randomized study was designed to compare the implicit memory during total intravenous versus inhalational anesthesia.MethodFourty patients ASA I and II undergoing orthopedic procedures under BIS-guided (40–60) general anesthesia were tested for implicit memory of previously introduced auditory material. Patients were divided into two groups (each group 20 patient). Group I, anesthesia was induced with propofol and maintained with propofol, fentanyl and cis-atracurium. Group II, anesthesia was induced with propofol and maintained with sevoflurane, fentanyl and cis-atracurium. Explicit memory was evaluated by asking four standard questions regarding intra-operative awareness. Free recall and recognition tests for implicit memory testing were carried out 30 min and 120 min after recovery.ResultsNo participant manifested explicit recall according to the 4-question interview. None of the patients gave a free recall of the presented items during anesthesia in the immediate and delayed tests of memory. In the recognition tests, immediate test (5%) and (0%) of the patients indicated correctly the presented words in TIVA and sevoflurane group respectively, in delayed test (10%) in TIVA group and (5%) in sevoflurane group. These results are not significant for implicit memory.ConclusionThere was no significant evidence of implicit memory in the two groups. BIS – controlled anesthesia appears to abolish implicit memory.

Intraoperative bispectral index monitoring and time to extubation after cardiac surgery: secondary analysis of a randomized controlled trial.

BackgroundFast track recovery is a care process goal after cardiac surgery. Intraoperative anesthetic depth may impact recovery, but the impact of brain monitoring on time to extubation and intensive care unit (ICU) length of stay after cardiac surgery has not been extensively studied. Our goal was to determine if BIS-guided anesthesia improves time to extubation compared to MAC-guided anesthesia in a cardiac surgery population.MethodsIn this secondary outcome analysis of a randomized controlled study, we analyzed 294 patients undergoing elective coronary bypass grafting, valve replacements, and bypass plus valve replacements at a single tertiary referral center between February 1, 2009 and April 30, 2010. We analyzed cardiac surgery patients that had been randomized to BIS-guided anesthesia alerts (n = 131) or MAC-guided anesthesia alerts (n = 163). The primary outcome measure was time to extubation in the BIS-guided and anesthetic concentration-guided groups. Secondary outcomes were length of stay in the ICU and total postoperative hospital length of stay.ResultsValid extubation time data were available for 247 of 294 patients. The median [IQR] time to extubation was 307 [215 to 771] minutes in the BIS group and 323 [196 to 730] minutes in the anesthetic concentration group (p = 0.61). The median [IQR] ICU length of stay was 54 [29 to 97] hours versus 70 [44 to 99] hours (p = 0.11). In terms of postoperative hospital length of stay, there was no difference between the groups with median [IQR] times of 6 [5-8] days (p = 0.69) in each group.ConclusionsThe use of intraoperative BIS monitoring during cardiac surgery did not change time to extubation, ICU length of stay or hospital length of stay. Data regarding BIS monitoring and recovery in an exclusively cardiac surgery population are consistent with recent effectiveness studies in the general surgical population.Trial registrationClinicalTrials.gov number NCT00689091.

Recovery from Anesthesia after Craniotomy for Supratentorial Tumors

Rapid recovery after supratentorial tumors (STT) removal is important. Short-acting anesthetics, such as propofol and remifentanil might favor this objective. The aim of this study was to compare the recovery of 2 Bispectral index (BIS)-guided anesthesia protocols combining sevoflurane-sufentanil (SS) or propofol-remifentanil (PR) administered during craniotomy for STT. After IRB approval and written consent, patients scheduled for surgical removal of STT were randomized to receive PR or SS. Anesthesia was adjusted to maintain BIS values between 45 and 55. The primary outcome was the time from discontinuation of anesthetics to extubation. Secondary endpoints were: time to respond to a simple order, and to achieve spontaneous ventilation, agitation score at emergence, postoperative Mini Mental State, postoperative Aldrete score, pain Visual Analogical Score, simplified sedation score, Glasgow Coma Scale, and surgical complications. Statistical analyses were performed using analysis of variance. Thirty-five and 31 were included in the SS and PR groups, respectively. Times to extubation was not different between the 2 groups (11.8±6.9 vs. 13.0±8.1 min in PR and SS groups, respectively, P=0.577). Although times to achieve an Aldrete score to 10, a Glasgow Coma Scale to 15, and a MMS to 30 significantly were lower in SS group, no significant difference was found when analyzing time course of these 3 factors over the first postoperative day. All other secondary endpoints were not different between the 2 groups. During craniotomy for STT, we could not demonstrate a reduction in the time to extubation when comparing a BIS-guided anesthesia associating PR to a BIS-guided anesthesia associating SS (Clinicatrials.gov identifier: NCT00389883).

The Impact of Bispectral Index Versus End-Tidal Anesthetic Concentration-Guided Anesthesia on Time to Tracheal Extubation in Fast-Track Cardiac Surgery

Bispectral Index (BIS)-guided anesthesia administration has been reported to reduce the time to tracheal extubation. However, no trials have compared the ability of BIS guidance to promote earlier tracheal extubation relative to guidance by end-tidal anesthetic concentration (ETAC). We hypothesized that BIS-guided anesthesia would result in earlier tracheal extubation compared with ETAC-guided anesthesia in fast-track cardiac surgery patients. This study consisted of patients at a single institution who were enrolled in the larger, multicenter BIS or Anesthesia Gas to Reduce Explicit Recall (BAG-RECALL) clinical trial that compared rates of postoperative awareness for patient whose anesthetic was guided by BIS versus ETAC. Patients undergoing cardiac surgery were randomized to BIS (n = 361) or ETAC (n = 362) guided anesthesia. Volatile anesthetic was titrated either to maintain a BIS value of 40 to 60 (BIS group), or an age-adjusted minimum alveolar concentration of 0.7 to 1.3 (ETAC group). In the ETAC group, anesthesiologists were blinded to the BIS values. In this substudy, time to tracheal extubation was compared between groups. Cox regression identified predictors affecting the instantaneous probability of tracheal extubation. Time to tracheal extubation was not significantly different between groups (odds ratio 1.04, 95% confidence interval, 0.88-1.23, P = 0.643). In addition, group assignment did not influence the instantaneous probability of tracheal extubation (P = 0.433). Predictors decreasing the instantaneous probability of tracheal extubation included higher body mass index (P = 0.001), higher logistic EuroSCORE (P = 0.015), complex surgery type (P = 0.034), and surgery completion in the evening (P = 0.03). Compared with management based on ETAC, anesthetic management based on BIS guidance does not strongly increase the probability of earlier tracheal extubation in patients undergoing fast-track cardiac surgery. The decision to extubate the trachea is more influenced by patient characteristics and perioperative course than the assignment to BIS or ETAC monitoring.

BIS-guided Anesthesia Decreases Postoperative Delirium and Cognitive Decline

Previous clinical trials and animal experiments have suggested that long-lasting neurotoxicity of general anesthetics may lead to postoperative cognitive dysfunction (POCD). Brain function monitoring such as the bispectral index (BIS) facilitates anesthetic titration and has been shown to reduce anesthetic exposure. In a randomized controlled trial, we tested the effect of BIS monitoring on POCD in 921 elderly patients undergoing major noncardiac surgery. Patients were randomly assigned to receive either BIS-guided anesthesia or routine care. The BIS group had anesthesia adjusted to maintain a BIS value between 40 and 60 during maintenance of anesthesia. Routine care group had BIS measured but not revealed to attending anesthesiologists. Anesthesia was adjusted according to traditional clinical signs and hemodynamic parameters. A neuropsychology battery of tests was administered before and at 1 week and 3 months after surgery. Results were compared with matched control patients who did not have surgery during the same period. Delirium was measured using the confusion assessment method criteria. The median (interquartile range) BIS values during the maintenance period of anesthesia were significantly lower in the control group, 36 (31 to 49), compared with the BIS-guided group, 53 (48 to 57), P<0.001. BIS-guided anesthesia reduced propofol delivery by 21% and that for volatile anesthetics by 30%. There were fewer patients with delirium in the BIS group compared with routine care (15.6% vs. 24.1%, P=0.01). Although cognitive performance was similar between groups at 1 week after surgery, patients in the BIS group had a lower rate of POCD at 3 months compared with routine care (10.2% vs. 14.7%; adjusted odds ratio 0.67; 95% confidence interval, 0.32-0.98; P=0.025). BIS-guided anesthesia reduced anesthetic exposure and decreased the risk of POCD at 3 months after surgery. For every 1000 elderly patients undergoing major surgery, anesthetic delivery titrated to a range of BIS between 40 and 60 would prevent 23 patients from POCD and 83 patients from delirium.

Pick up the Pieces

Pick up the Pieces

The effect of cerebral monitoring on recovery after sevoflurane anesthesia in ambulatory setting in children: A comparison among bispectral index, A-line autoregressive index, and standard practice

Background The bispectral index (BIS) and A-line autoregressive index (AAI) are electroencephalogram-derived monitoring indices of anesthesia. This study evaluated the efficacy of BIS- and AAI-guided sevoflurane anesthesia in children receiving ambulatory urologic surgeries. Methods One hundred sixty children (aged 3–12 years) undergoing ambulatory urologic surgery were randomized to receive sevoflurane anesthesia controlled either solely by clinical parameters (standard practice group), BIS-guided group within the BIS range of 40–60 (BIS group), or AAI-guided group within the AAI range of 15–30 (AAI group). The primary outcome was the recovery time, and the secondary outcome was the quality of recovery, including the incidence of emergency delirium measured by Pediatric Anesthesia Emergence Delirium score, incidence of postoperative nausea and vomiting, and parental satisfaction. Results Compared with the standard practice group, patients with BIS or AAI monitoring had shortened recovery time and consumed less sevoflurane. There were no significant differences in the incidences of emergence delirium, postoperative nausea and vomiting, or parental satisfaction among the three groups. Conclusion BIS- and AAI- guided titration sevoflurane anesthesia could result in shortened recovery and reduced sevoflurane concentration and consumption without affecting the quality of recovery in children receiving ambulatory urologic surgery. The beneficial effects of AAI- and BIS-guided anesthesia in pediatric ambulatory surgeries are similar.

No benefit of manually BIS-guided anesthesia in children: is anesthesia really guided by BIS?

No benefit of manually BIS-guided anesthesia in children: is anesthesia really guided by BIS?

The Effect of Bispectral Index Monitoring on Long-Term Survival in the B-Aware Trial

When anesthesia is titrated using bispectral index (BIS) monitoring, patients generally receive lower doses of hypnotic drugs. Intraoperative hypotension and organ toxicity might be avoided if lower doses of anesthetics are administered, but whether this translates into a reduction in serious morbidity or mortality remains controversial. The B-Aware Trial randomly allocated 2463 patients at high risk of awareness to BIS-guided anesthesia or routine care. We tested the hypothesis that the risks of death, myocardial infarction (MI), and stroke would be lower in patients allocated to BIS-guided management than in those allocated to routine care. The medical records of all patients who had not died within 30 days of surgery were reviewed. The date and cause of death and occurrence of MI or stroke were recorded. A telephone interview was then conducted with all surviving patients. The primary end point of the study was survival. The median follow-up time was 4.1 (range: 0-6.5) years. Five hundred forty-eight patients (22.2%) had died since the index surgery, 220 patients (8.9%) had an MI, and 115 patients (4.7%) had a stroke. The risk of death in BIS patients was not significantly different than in routine care patients (hazard ratio = 0.86 [95% confidence interval {CI}: 0.72-1.01]; P = 0.07). However, propensity score analysis indicated that the hazard ratio for death in patients who recorded BIS values <40 for >5 min compared with other BIS-monitored patients was 1.41 (95% CI: 1.02-1.95; P = 0.039). In addition, the odds ratios for MI in patients who recorded BIS values <40 for >5 min compared with other BIS-monitored patients was 1.94 (95% CI: 1.12-3.35; P = 0.02) and the odds ratio for stroke was 3.23 (95% CI: 1.29-8.07; P = 0.01). Monitoring with BIS and absence of BIS values <40 for >5 min were associated with improved survival and reduced morbidity in patients enrolled in the B-Aware Trial.