Cardiovascular and pulmonary effects of romifidine and butorphanol combination in horses

Abstract

The effects of romifidine (60µg/kg) and butorphanol (40µg/kg) combination were studied in eight horses. The parameters were measured before (T0) and 10 (T1), 15 (T2), 30 (T3), 40 (T4) and 65 (T5) minutes after sedation. Heart rate, cardiac output and cardiac index decreased significantly post-treatment. A significant increase was present in pulmonary arterial pressure, pulmonary arterial wedge pressure, central venous pressure and systemic vascular resistance values at post-treatment period. Systolic, mean and diastolic arterial pressures, stroke index and pulmonary vascular resistance did not change significantly. Respiratory rate, mixed venous saturation of oxygen, mixed venous oxygen content and oxygen delivery index decreased significantly post-treatment. Arterial partial pressure of oxygen, arterial saturation of oxygen, mixed venous partial pressure of oxygen, arterial oxygen content, arteriovenous oxygen content difference, oxygen consumption index, oxygen extraction ratio, pH and arterial bicarbonate did not change significantly. The partial pressure of carbon dioxide increased significantly 40 minutes post-treatment. The romifidine and butorphanol combination produced cardiovascular depression similar to those reported with romifidine used alone.