Effect of Remimazolam Versus Dexmedetomidine on the Incidence of Delirium After Elective Cardiac Surgery with Cardiopulmonary Bypass: a Prospective Randomized Controlled Trial

Delirium is an acute brain dysfunction characterized by an acute onset and fluctuating course of disturbance in attention, awareness, and cognition, It is the most common neurocognitive complication following cardiac surgery, with an incidence rate between 11% and 52%. The occurrence of delirium correlates strongly with various short- and long-term poor outcomes following cardiac surgery, including prolonged ICU stay and hospitalization and increased risk of hospital readmission. Different risk factors contribute to delirium after cardiac surgery, including advanced age, pre-existing cognitive impairment, diabetes, history of stroke, type of surgery, extended CPB duration, and blood transfusion. Dexmedetomidine is a highly and potently selective α2-adrenoceptor agonist with anxiolytic, sedative, and analgesic properties. It has neuroprotective effects by reducing neuroinflammation, apoptosis, and blood-brain barrier injury via central α2A adrenoceptors, but it can cause hypotension and bradycardia. Remimazolam, a new ultra-short-acting benzodiazepine, also has a faster onset of action and a higher safety profile. It was recently approved for procedural sedation and general anesthesia. Its metabolism is mainly induced by tissue esterase, independent of liver and kidney function, and its metabolites are inactive. In addition, flumazenil reverses the effects of Remimazolam in the event of adverse events, an advantage not available in non-benzodiazepines. The objective of this clinical trial is to evaluate the efficacy of Remimazolam compared with Dexmedetomidine for preventing postoperative delirium after cardiac surgery.