Cardiopulmonary effects of a xylazine and ketamine combination in pigs.

The carotid and pulmonary arteries were catheterised in six pigs anaesthetised with thiopentone sodium and halothane. A minimum of five days was allowed to elapse before the investigation. The carotid artery pressure, pulmonary artery pressure, cardiac output, arterial pH, PO2, PCO2, plasma glucose and lactate were measured before and after intravenous injection of xylazine (1 mg kg-1) and ketamine 10 mg kg-1). Complete analgesia was produced for 10 minutes in all pigs but by 25 minutes all animals responded to a painful stimulus. The cardiac output and arterial PO2 were significantly decreased for 30 minutes and 10 minutes, respectively. The total vascular resistance was significantly increased. No statistically significant changes occurred in the other variables measured.