Benzodiazepine-Free Cardiac Anesthesia for Reduction of Postoperative Delirium (B-Free): A Protocol for a Multi-centre Randomized Cluster Crossover Trial
Jessica Spence, Emilie P. Belley‐Côté, Eric Jacobsohn, Shun Fu Lee, Frédérick D’Aragon, Michael S. Avidan, C. David Mazer, Nicolas Rousseau‐Saine, Raja Rajamohan, Kane O. Pryor, Rael Klein, Edmund Tan, Matthew Cameron, Emily Di Sante, Erin DeBorba, M. Mustard, Étienne J. Couture, Raffael Pereira Cezar Zamper, Michael R. Law, George Djaiani, Tarit Saha, Stephen Choi, Peter Hedlin, Ryan Pikaluk, Wing Lam, Alain Deschamps, Richard Whitlock, Braden J. Dulong, P.J. Devereaux, Chris Beaver, Shelley Kloppenburg, Simon Oczkowski, William F. McIntyre, Matthew Ryan McFarling, André Lamy, Jessica Vincent, Stuart J. Connolly
Abstract
Delirium is common after cardiac surgery and associated with adverse outcomes. Benzodiazepine administration before and after cardiac surgery is associated with delirium; guidelines recommend minimizing their use. Benzodiazepine administration during cardiac surgery remains common because of recognized benefits. B-Free is a randomized cluster crossover trial evaluating whether an institutional policy of restricted intraoperative benzodiazepine administration (i.e., ≥90% of patients do not receive benzodiazepines during cardiac surgery) compared with a policy of liberal intraoperative benzodiazepine administration (i.e., ≥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 as 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, four-week crossover periods. Randomization for all periods takes place in advance of site start-up; 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 up to 72 hours after surgery. B-Free will enrol ≥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. B-Free will determine whether an institutional policy restricting the administration of benzodiazepines during cardiac surgery reduces the incidence of delirium after cardiac surgery.