The effect of CPR on plasma diltiazem concentrations in dogs.

Abstract

To determine the effect of cardiac arrest with CPR on diltiazem concentrations in dogs. Prospective, double-blind, randomized trial. Laboratory at a large university-affiliated medical center. Twenty mongrel dogs. Following administration of anesthesia, catheters were placed in the pulmonary artery, aortic arch, left ventricle, and right ventricle. Dogs were randomized to receive diltiazem (0.5 mg/kg) either 60 minutes before or during cardiac arrest with CPR. After 13 minutes of cardiac arrest, defibrillation was attempted. Frequent blood samples for diltiazem concentrations were obtained before, during, and after cardiac arrest. The mean diltiazem concentration rose 70% during CPR in the group that received diltiazem before cardiac arrest. The group that received diltiazem during CPR had concentrations five times greater than expected during sinus rhythm. Increased diltiazem concentrations are observed during CPR and are probably related to altered distribution encountered during CPR.