Hemodynamic Effects of Interpleural Lidocaine and Bupivacaine Combination in Anesthetized Dogs with and Without an Open Pericardium

To identify dysrhythmias and hemodynamic changes after lidocaine and bupivacaine infusion into the interpleural space with an open pericardium. Experimental study. Six adult dogs. Systemic arterial pressure and electrocardiogram were recorded. A 7.5 Fr Swan-Ganz catheter was advanced to the level of the main pulmonary artery to record pulmonary arterial pressure. Cardiac output was measured by a thermodilution technique. A pericardial window (PW) was performed in 3 dogs using thoracoscopy. Hemodynamic variables were recorded before and 15 minutes after injection of lidocaine (1.5 mg/kg) and bupivacaine (1.5 mg/kg) into the pleural space in the control group and in the pericardial space for the PW group. A randomized-block ANOVA for repeated measures was used to evaluate the effect of local anesthetic administration on hemodynamic and electrophysiologic variables in dogs with a pericardectomy. Each dog maintained sinus rhythm. Infusion of local anesthetic induced a significant increase in right ventricular diastolic pressure (P=.002) and a significant decrease in stroke volume (P=.047) in both groups; however, the effects were not significantly different between groups. Infusion of lidocaine and bupivacaine, either intrapleural or in the pericardial space, had a mild detrimental effect on cardiac output. Intrapleural administration of lidocaine and bupivacaine at a therapeutic dose can be used safely in healthy dogs with a pericardectomy.