The effect of perioperative benzodiazepine administration on postoperative nausea and vomiting: a systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: Despite recent systematic reviews suggesting their benefit for postoperative nausea, vomiting, or both (PONV) prevention, benzodiazepines have not been incorporated into guidelines for PONV prophylaxis because of concerns about possible adverse effects. We conducted an updated meta-analysis to inform future practice guidelines. METHODS: We included randomised controlled trials (RCTs) of all languages comparing benzodiazepines with non-benzodiazepine comparators in adults undergoing inpatient surgery. Our outcomes were postoperative nausea, vomiting, or both. We assessed risk of bias for RCTs using the Cochrane Risk of Bias tool. We pooled data using a random-effects model and assessed the quality of evidence for each outcome using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. RESULTS: We screened 31 413 abstracts and 950 full texts. We included 119 RCTs; 104 were included in quantitative synthesis. Based on moderate certainty evidence, we found that perioperative benzodiazepine administration reduced the incidence of PONV (52 studies, n=5086, relative risk [RR]: 0.77, 95% confidence interval [CI] 0.66-0.89; number needed to treat [NNT] 16; moderate certainty), postoperative nausea (55 studies, n=5916, RR: 0.72, 95% CI 0.62-0.83; NNT 21; moderate certainty), and postoperative vomiting (52 studies, n=5909, RR: 0.74, 95% CI 0.60-0.91; NNT 55; moderate certainty). CONCLUSIONS: Moderate quality evidence shows that perioperative benzodiazepine administration decreases the incidence of PONV. The results of this systematic review and meta-analysis will inform future clinical practice guidelines. SYSTEMATIC REVIEW PROTOCOL: The protocol for this systematic review was pre-registered with PROSPERO International Prospective Register of Systematic Reviews (CRD42022361088) and published in BMJ Open (PMID 31831540).

Benzodiazepine-Free Cardiac Anesthesia for Reduction of Postoperative Delirium (B-Free): A Protocol for a Multi-centre Randomized Cluster Crossover Trial.

Delirium is common after cardiac surgery and is associated with adverse outcomes. Administration of benzodiazepines before and after cardiac surgery is associated with delirium; guidelines recommend minimizing their use. Benzodiazepine administration during cardiac surgery remains common because of its recognized benefits. The Benzodiazepine-Free Cardiac Anesthesia for Reduction of Postoperative Delirium (B-Free) trial is a randomized cluster crossover trial evaluating whether an institutional policy of restricting intraoperative benzodiazepine administration (ie, ≥ 90% of patients do not receive benzodiazepines during cardiac surgery), as compared with a policy of liberal intraoperative benzodiazepine administration (ie, ≥ 90% of patients receive ≥ 0.03 mg/kg midazolam equivalent), reduces delirium. Hospitals performing ≥ 250 cardiac surgeries a year are included if their cardiac anesthesia group agrees to apply both benzodiazepine policies per their randomization, and patients are assessed for postoperative delirium every 12 hours in routine clinical care. Hospitals apply the restricted or liberal benzodiazepine policy during 12 to 18 crossover periods of 4 weeks each. Randomization for all periods takes place in advance of site startup; sites are notified of their allocated policy during the last week of each crossover period. Policies are applied to all patients undergoing cardiac surgery during the trial period. The primary outcome is the incidence of delirium at up to 72 hours after surgery. The B-Free trial will enroll ≥ 18,000 patients undergoing cardiac surgery at 20 hospitals across North America. Delirium is common after cardiac surgery, and benzodiazepines are associated with the occurrence of delirium. The B-Free trial will determine whether an institutional policy restricting the administration of benzodiazepines during cardiac surgery reduces the incidence of delirium after cardiac surgery. Clinicaltrials.gov registration number: NCT03928236 (First registered April 26, 2019).

L'état confusionnel est fréquent après une chirurgie cardiaque et il est associé à des complications. L'administration de benzodiazépines avant et après une chirurgie cardiaque est associée à l'état confusionnel; dans les lignes directrices, on recommande de réduire leur utilisation au minimum. L'administration de benzodiazépines pendant une chirurgie cardiaque demeure fréquente, en raison des leurs bienfaits reconnus. L'essai B-Free (Benzodiazepine-Free Cardiac Anesthesia for Reduction of Postoperative Delirium ou l'anesthésie sans benzodiazépine en contexte de chirurgie cardiaque pour la réduction de l'état confusionnel postopératoire) est un essai à répartition aléatoire par grappes et avec permutation, visant à évaluer si une politique institutionnelle de restriction de l'administration peropératoire de benzodiazépines (c.-à-d. que ≥ 90 % des patients ne reçoivent pas de benzodiazépines durant une chirurgie cardiaque) réduit l'état confusionnel, comparativement à une politique d'administration peropératoire libérale de benzodiazépines (c.-à-d. que ≥ 90 % des patients reçoivent ≥ 0,03 mg/kg d'équivalent du midazolam). Des hôpitaux effectuant au moins 250 chirurgies cardiaques par année sont inclus dans l'essai si leurs équipes d'anesthésie cardiaque acceptent d'appliquer les deux politiques relatives aux benzodiazépines en vertu de la répartition aléatoire et si les patients sont évalués toutes les 12 heures, en ce qui a trait à l'état confusionnel postopératoire, dans le cadre des soins cliniques habituels. Les hôpitaux mettent en œuvre la politique d'administration restreinte ou libérale de benzodiazépines durant 12 à 18 périodes de permutation de 4 semaines chacune. La répartition aléatoire de l'ensemble des périodes a lieu avant le début de l'essai à l'hôpital; les établissements sont avisés de la politique qui leur est attribuée au cours de la dernière semaine de chaque période de permutation. Les politiques sont appliquées à tous les patients qui subissent une chirurgie cardiaque durant la période de l'essai. Le critère d'évaluation principal est l'incidence de l'état confusionnel dans les 72 heures suivant l'intervention chirurgicale. L'étude B-Free inclura au moins 18 000 patients qui subiront une chirurgie cardiaque dans 20 hôpitaux en l'Amérique du Nord. L'état confusionnel est fréquent après une chirurgie cardiaque, et les benzodiazépines sont associées à la survenue de l'état confusionnel. L'essai B-Free permettra de déterminer si une politique institutionnelle de restriction de l'administration de benzodiazépines durant une chirurgie cardiaque réduit l'incidence de l'état confusionnel après une telle chirurgie.Clinicaltrials.gov registration number: NCT03928236 (First registered April 26, 2019).

Effect of perioperative benzodiazepine use on intraoperative awareness and postoperative delirium: a systematic review and meta-analysis of randomised controlled trials and observational studies.

BACKGROUND: Benzodiazepine use is associated with delirium, and guidelines recommend avoiding them in older and critically ill patients. Their perioperative use remains common because of perceived benefits. METHODS: We searched CENTRAL, MEDLINE, CINAHL, PsycInfo, and Web of Science from inception to June 2021. Pairs of reviewers identified randomised controlled trials and prospective observational studies comparing perioperative use of benzodiazepines with other agents or placebo in patients undergoing surgery. Two reviewers independently abstracted data, which we combined using a random-effects model. Our primary outcomes were delirium, intraoperative awareness, and mortality. RESULTS: We included 34 randomised controlled trials (n=4354) and nine observational studies (n=3309). Observational studies were considered separately. Perioperative benzodiazepines did not increase the risk of delirium (n=1352; risk ratio [RR] 1.43; 95% confidence interval [CI]: 0.9-2.27; I2=72%; P=0.13; very low-quality evidence). Use of benzodiazepines instead of dexmedetomidine did, however, increase the risk of delirium (five studies; n=429; RR 1.83; 95% CI: 1.24-2.72; I2=13%; P=0.002). Perioperative benzodiazepine use decreased the risk of intraoperative awareness (n=2245; RR 0.26; 95% CI: 0.12-0.58; I2=35%; P=0.001; very low-quality evidence). When considering non-events, perioperative benzodiazepine use increased the probability of not having intraoperative awareness (RR 1.07; 95% CI: 1.01-1.13; I2=98%; P=0.03; very low-quality evidence). Mortality was reported by one randomised controlled trial (n=800; RR 0.90; 95% CI: 0.20-3.1; P=0.80; very low quality). CONCLUSIONS: In this systematic review and meta-analysis, perioperative benzodiazepine use did not increase postoperative delirium and decreased intraoperative awareness. Previously observed relationships of benzodiazepine use with delirium could be explained by comparisons with dexmedetomidine. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42019128144.