Intraoperative bispectral index monitoring and time to extubation after cardiac surgery: secondary analysis of a randomized controlled trial.
ABSTRACT: Fast 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.In 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.Valid 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.The 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.ClinicalTrials.gov number NCT00689091.
Project description:Postoperative delirium in the intensive care unit (ICU) is a frequent complication after cardiac or thoracic surgery and is associated with increased morbidity and mortality.In this single-center substudy of the BAG-RECALL trial (NCT00682825), we screened patients after cardiac or thoracic surgery in the ICU twice daily for delirium using the Confusion Assessment Method for the ICU. The primary outcome was the incidence of delirium in patients who had been randomized to intraoperative Bispectral Index (BIS)-guided and end-tidal anesthetic concentration-guided depth of anesthesia protocols. As a secondary analysis, a Bayesian stochastic search variable selection strategy was used to rank a field of candidate risk factors for delirium, followed by binary logistic regression.Of 310 patients assessed, 28 of 149 (18.8%) in the BIS group and 45 of 161 (28.0%) in the end-tidal anesthetic concentration group developed postoperative delirium in the ICU (odds ratio 0.60, 95% confidence interval, 0.35-1.02, P= 0.058). Low average volatile anesthetic dose, intraoperative transfusion, ASA physical status, and European System for Cardiac Operative Risk Evaluation were identified as independent predictors of delirium.A larger randomized study should determine whether brain monitoring with BIS or an alternative method decreases delirium after cardiac or thoracic surgery. The association between low anesthetic concentration and delirium is a surprising finding and could reflect that patients with poor health are both more sensitive to the effects of volatile anesthetic drugs and are also more likely to develop postoperative delirium. Investigation of candidate methods to prevent delirium should be prioritized in view of the established association between postoperative delirium and adverse patient outcomes.
Project description:Background: There is some evidence that electroencephalography guidance of general anesthesia can decrease postoperative delirium after non-cardiac surgery. There is limited evidence in this regard for cardiac surgery. A suppressed electroencephalogram pattern, occurring with deep anesthesia, is associated with increased incidence of postoperative delirium (POD) and death. However, it is not yet clear whether this electroencephalographic pattern reflects an underlying vulnerability associated with increased incidence of delirium and mortality, or whether it is a modifiable risk factor for these adverse outcomes. Methods: The Electroe ncephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes ( ENGAGES-Canada) is an ongoing pragmatic 1200 patient trial at four Canadian sites. The study compares the effect of two anesthetic management approaches on the incidence of POD after cardiac surgery. One approach is based on current standard anesthetic practice and the other on electroencephalography guidance to reduce POD. In the guided arm, clinicians are encouraged to decrease anesthetic administration, primarily if there is electroencephalogram suppression and secondarily if the EEG index is lower than the manufacturers recommended value (bispectral index (BIS) or WAVcns below 40 or Patient State Index below 25). The aim in the guided group is to administer the minimum concentration of anesthetic considered safe for individual patients. The primary outcome of the study is the incidence of POD, detected using the confusion assessment method or the confusion assessment method for the intensive care unit; coupled with structured delirium chart review. Secondary outcomes include unexpected intraoperative movement, awareness, length of intensive care unit and hospital stay, delirium severity and duration, quality of life, falls, and predictors and outcomes of perioperative distress and dissociation. Discussion: The ENGAGES-Canada trial will help to clarify whether or not using the electroencephalogram to guide anesthetic administration during cardiac surgery decreases the incidence, severity, and duration of POD. Registration: ClinicalTrials.gov ( NCT02692300) 26/02/2016.
Project description:Purpose:In this study, the effect of intravenous vitamin C during surgery on the incidence of postoperative pulmonary complications (PPCs) in patients undergoing cardiopulmonary bypass and cardiac surgery was observed, and its protective effect on the lungs was evaluated to provide a reference for clinical medication. Patients and Methods:Patients undergoing cardiac surgery under cardiopulmonary bypass (CPB) were selected. The patients were divided into group A and group C by random sequence. Patients in group A received intravenous vitamin C 1 g 10 minutes after induction of anesthesia, 10 minutes before cardiac reanimation and at the moment of sternal closure. Patients in group C were intravenously injected with the same volume of saline at the same time. The primary outcome was the postoperative pulmonary complication severity score. Other outcomes were the incidence of PPCs, awakening time, extubation time, length of ICU stay, length of hospital stay, adverse events, oxygenation index (PaO2/FiO2), alveolar arterial oxygen partial pressure difference (A-aDO2), dynamic lung compliance (Cd) and static lung compliance (Cs). Results:Seventy patients completed the study. Compared to group C, the postoperative pulmonary complication score [2(2-3) vs 2(1-2); P=0.009] and the incidence of postoperative pulmonary complications (32.43% vs 12.12%; P =0.043) were lower in group A. There were no significant differences in awakening time, extubation time, length of ICU stay, length of hospital stay, adverse events, PaO2/FiO2, A-aDO2, Cs, and Cd between the two groups (P>0.05). Conclusion:In summary, this small randomized trial including low-risk cardiac surgery patients shows that intravenous vitamin C may safely be administered and may be helpful to prevent PPCs after cardiac surgery.
Project description:BACKGROUND:We theorized that modafinil, an atypical psychomotor stimulant, utilized to improve daytime somnolence in patients with obstructive sleep apnea, would improve functional recovery after general anesthesia by improving time to extubation, post-anesthesia care unit (PACU) length of stay and subjective recovery after general anesthesia. METHODS:A double blind, randomized, placebo-controlled pilot study was performed. 102 patients with the diagnosis of obstructive sleep apnea (OSA) were randomized to receive either 200?mg of modafinil or placebo before general anesthesia. The trial was terminated for futility. The primary outcome was PACU length of stay between groups. Secondary functional metrics of improved post-anesthesia recovery were compared between groups. RESULTS:No difference between groups was found on the primary outcome of PACU length of stay (PACULOS). Emergence from general anesthesia was not significantly different when assessed by the time period between termination of volatile anesthetic and extubation. Similarly, no difference between groups was found in intraoperative bispectral index (BIS) values, postoperative pain scores or narcotic consumption (morphine equivalent units). In the post-anesthesia care unit, respiratory rate was increased and mean arterial pressure was lower in the modafinil group. CONCLUSIONS:Our results suggest that the use of single-dose preoperative modafinil may not improve functional recovery after general anesthesia in patients with the diagnosis of OSA. Further research is needed before use of atypical psychomotor stimulants in this surgical population.
Project description:Volatile sedation in the intensive care unit (ICU) may reduce the number of adverse events and improve patient outcomes compared with intravenous (IV) sedation. We performed a systematic review and meta-analysis comparing the effects of volatile and IV sedation in adult ICU patients.We searched the PubMed, Embase, Cochrane Central Register, and Web of Science databases for all randomized trials comparing volatile sedation using an anesthetic-conserving device (ACD) with IV sedation in terms of awakening and extubation times, lengths of ICU and hospital stay, and pharmacologic end-organ effects.Thirteen trials with a total of 1027 patients were included. Volatile sedation (sevoflurane or isoflurane) administered through an ACD shortened the awakening time [mean difference (MD), -80.0?minutes; 95% confidence intervals (95% CIs), -134.5 to -25.6; P?=?.004] and extubation time (MD, -196.0?minutes; 95% CIs, -305.2 to -86.8; P?<?.001) compared with IV sedation (midazolam or propofol). No differences in the lengths of ICU and hospital stay were noted between the 2 groups. In the analysis of cardiac effects of sedation from 5 studies, patients who received volatile sedation showed lower serum troponin levels 6?hours after ICU admission than patients who received IV sedation (P?<?.05). The effect size of troponin was largest between 12 and 24?hours after ICU admission (MD, -0.27??g/L; 95% CIs, -0.44 to -0.09; P?=?.003).Compared with IV sedation, volatile sedation administered through an ACD in the ICU shortened the awakening and extubation times. Considering the difference in serum troponin levels between both arms, volatile anesthetics might have a myocardial protective effect after cardiac surgery even at a subanesthetic dose. Because the included studies used small sample sizes with high heterogeneity, further large, high-quality prospective clinical trials are needed to confirm our findings.
Project description:To evaluate the impact of volatile anesthetic choice on clinically relevant outcomes of patients undergoing cardiac surgery.Major databases were systematically searched for randomized controlled trials (RCTs) comparing volatile anesthetics (isoflurane versus sevoflurane) in cardiac surgery. Study-level characteristics, intraoperative events, and postoperative outcomes were extracted from the articles.Sixteen RCTs involving 961 patients were included in this meta-analysis. There were no significant differences between both anesthetics in terms of intensive care unit length of stay (SMD -0.07, 95% CI -0.38 to 0.24, P = 0.66), hospital length of stay (SMD 0.06, 95% CI -0.33 to 0.45, P = 0.76), time to extubation (SMD 0.29, 95% CI -0.08 to 0.65, P = 0.12), S100? (at the end of surgery: SMD 0.08, 95% CI -0.33 to 0.49, P = 0.71; 24 hours after surgery: SMD 0.21, 95% CI -0.23 to 0.65, P = 0.34), or troponin (at the end of surgery: SMD -1.13, 95% CI -2.39 to 0.13, P = 0.08; 24 hours after surgery: SMD 0.74, 95% CI -0.15 to 1.62, P = 0.10). CK-MB was shown to be significantly increased when using isoflurane instead of sevoflurane (SMD 2.16, 95% CI 0.57 to 3.74, P = 0.008).The volatile anesthetic choice has no significant impact on postoperative outcomes of patients undergoing cardiac surgery.
Project description:Awareness 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.BAG-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.This 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.ClinicalTrials.gov Identifier: NCT00682825.
Project description:Cardiac surgery presents particular challenges for the anesthesiologist. In addition to standard and advanced monitors typically used during cardiac surgery, anesthesiologists may consider monitoring the brain with raw or processed electroencephalography (EEG). There is strong evidence that a protocol incorporating the processed EEG bispectral index (BIS) decreases the incidence intraoperative awareness in comparison with standard practice. However, there is conflicting evidence that incorporating the BIS into cardiac anesthesia practice improves "fast-tracking," decreases anesthetic drug use, or detects cerebral ischemia. Recent research, including many cardiac surgical patients, shows that a protocol based on BIS monitoring is not superior to a protocol based on end-tidal anesthetic concentration monitoring in preventing awareness. There has been a resurgence of interest in the anesthesia literature in limited montage EEG monitoring, including nonproprietary processed indices. This has been accompanied by research showing that with structured training, anesthesiologists can glean useful information from the raw EEG trace. In this review, we discuss both the hypothesized benefits and limitations of BIS and frontal channel EEG monitoring in the cardiac surgical population.
Project description:BACKGROUND:Traditionally, anesthesiologists have relied on nonspecific subjective and objective physical signs to assess patients' comfort level and depth of anesthesia. Commercial development of electrical monitors, which use low- and high-frequency electroencephalogram (EEG) signals, have been developed to enhance the assessment of patients' level of consciousness. Multiple studies have shown that monitoring patients' consciousness levels can help in reducing drug consumption, anesthesia-related adverse events, and recovery time. This clinical study will provide information by simultaneously comparing the performance of the SNAP II (a single-channel EEG device) and the bispectral index (BIS) VISTA (a dual-channel EEG device) by assessing their efficacy in monitoring different anesthetic states in patients undergoing general anesthesia. OBJECTIVE:The primary objective of this study is to establish the range of index values for the SNAP II corresponding to each anesthetic state (preinduction, loss of response, maintenance, first purposeful response, and extubation). The secondary objectives will assess the range of index values for BIS VISTA corresponding to each anesthetic state compared to published BIS VISTA range information, and estimate the area under the curve, sensitivity, and specificity for both devices. METHODS:This is a multicenter, prospective, double-arm, parallel assignment, single-blind study involving patients undergoing elective surgery that requires general anesthesia. The study will include 40 patients and will be conducted at the following sites: The Ohio State University Medical Center (Columbus, OH); Northwestern University Prentice Women's Hospital (Chicago, IL); and University of Miami Jackson Memorial Hospital (Miami, FL). The study will assess the predictive value of SNAP II versus BIS VISTA indices at various anesthetic states in patients undergoing general anesthesia (preinduction, loss of response, maintenance, first purposeful response, and extubation). The SNAP II and BIS VISTA electrode arrays will be placed on the patient's forehead on opposite sides. The hemisphere location for both devices' electrodes will be equally alternated among the patient population. The index values for both devices will be recorded and correlated with the scorings received by performing the Modified Observer's Assessment of Alertness and Sedation and the American Society of Anesthesiologists Continuum of Depth of Sedation, at different stages of anesthesia. RESULTS:Enrollment for this study has been completed and statistical data analyses are currently underway. CONCLUSIONS:The results of this trial will provide information that will simultaneously compare the performance of SNAP II and BIS VISTA devices, with regards to monitoring different anesthesia states among patients. CLINICALTRIAL:Clinicaltrials.gov NCT00829803; https://clinicaltrials.gov/ct2/show/NCT00829803 (Archived by WebCite at http://www.webcitation.org/6nmyi8YKO).
Project description:BACKGROUND:Diaphragm paresis is common after cardiac surgery and may delay the weaning from the ventilator. Our objective was to evaluate diaphragm thickening during weaning and secondly the muscle thickness as a marker of myotrauma. METHODS:Patients undergoing elective cardiac surgery were prospectively included. Ultrasonic index of right hemidiaphragm thickening fraction (TF) was measured as a surrogate criterion of work of breathing. A TF?<?20% was defined as a low diaphragm thickening. Measurements of TF were performed during three periods to study diaphragm thickening evolution defined by the difference between two consecutive time line point: preoperative (D?-?1), during a spontaneous breathing trial (SBT) in the intensive care unit and postoperative (D?+?1). We studied three patterns of diaphragm thickness at end expiration evolution from D?-?1 to D?+?1:?>?10% decrease, stability and?>?10% increase. Demographical data, length of surgery, type of surgery, ICU length of stay (LOS) and extubation failure were collected. RESULTS:Of the 100 consecutively included patients, 75 patients had a low diaphragm thickening during SBT. Compared to TF values at D?-?1 (36%?±?18), TF was reduced during SBT (17%?±?14) and D?+?1 (12%?±?11) (P?<?0.0001). Thickness and TF did not change according to the type of surgery or cooling method. TF at SBT was correlated to the length of surgery (both r?=?-?0.4; P?<?0.0001). Diaphragm thickness as continuous variable did not change over time. Twenty-eight patients (42%) had a?>?10% decrease thickness, 19 patients (29%) stability and 19 patients (28%) in?>?10% increase, and this thickness evolution pattern was associated with: a longer LOS 3 days [2-5] versus 2 days [2-4] and 2 days , respectively (ANOVA P?=?0.046), and diaphragm thickening evolution (ANOVA P?=?0.02). Two patients experience extubation failure. CONCLUSION:These findings indicate that diaphragm thickening is frequently decreased after elective cardiac surgery without impact on respiratory outcome, whereas an altered thickness pattern was associated with a longer length of stay in the ICU. Contractile activity influenced thickness evolution. Trial registry number ClinicalTrial.gov ID NCT02208479.