Cardiopulmonary effects during anaesthesia induced and maintained with propofol in acepromazine pre-medicated donkeys

Abstract

ObjectiveTo evaluate the cardiopulmonary effects of anaesthesia induced and maintained with propofol in acepromazine pre-medicated donkeys. Study designProspective experimental study. AnimalsSix healthy male donkeys weighing 78–144 kg. MethodsDonkeys were pre-medicated with intravenous (IV) acepromazine (0.04 mg kg−1). Ten minutes later, anaesthesia was induced with IV propofol (2 mg kg−1) and anaesthesia maintained by continuous IV infusion of the propofol (0.2 mg kg−1 minute−1) for 30 minutes. Baseline measurements of physiological parameters, and arterial blood samples were taken before the acepromazine administration, then 5, 15, 30, 45, and 60 minutes after the induction of anaesthesia. Changes from baseline were analysed by anova for repeated measures. ResultsWhen compared with baseline (standing) values, during anaesthesia heart rate increased throughout: significant at 5 (p = 0.001) and 15 (p = 0.015) minutes. Mean arterial blood pressure increased significantly only at 15 minutes (p < 0.001). Respiratory rate and arterial pH did not change significantly. PaO2 was lower throughout anaethesia, but this only reached significance at 15 minutes (p = 0.041). PaCO2 was statistically (but not clinically) significantly reduced at the times of 30 (p = 0.02), 45 (p = 0.01) and 60 (p = 0.04). Rectal temperature decreased significantly at all times of the study. Conclusions and clinical relevanceAdministration of propofol by the continuous infusion rate for the maintenance of anaesthesia resulted in stable cardiopulmonary effects and could prove to be clinically useful in donkeys.