Premedication of a patient with severe AS and MR must be approached with caution. The patient should receive supplemental oxygen. Small intravenous (IV) doses of sedation (eg, midazolam 0.5 mg) can be administered while the patient is closely monitored in the operating room with oxygen supplementation. It is important to remember that there can be delay in the onset of sedation secondary to pooling in the pulmonary circulation, and slow titration is essential to avoid inadvertent overdose, which can cause respiratory depression, pulmonary hypertension, and systemic hypotension. In older patients, use of benzodiazepines has been linked to postoperative delirium, which can be quite severe and difficult to treat increasing hospital length of stay and resource utilization.

References

• Spence J, Belley-Cote E, Jacobsohn E, et al. Restricted versus liberal intraoperative benzodiazepine use in cardiac anaesthesia for reducing delirium (B-Free Pilot): a pilot, multicentre, randomised, cluster crossover trial. Br J Anaesth. 2020;125:38-46.