Abstract
This study examined the analgesic and cardiopulmonary effects of intravenous (IV) tramadol during general intravenous anesthesia in calves. Calves were premedicated with diazepam (0.2 mg/kg, IV) with tramadol (2 mg/kg, IV) (group T) or saline (group S). Anesthesia was induced by thiamylal sodium (4 mg/kg, IV) and maintained with an infusion (2 ml/kg/hr) of 5% guaifenesin containing thiamylal sodium (2 mg/ml). Additional thiamylal sodium (1-2 mg/kg, IV) was administered when interference from the calves was observed during surgery. The total counts of additional thiamylal sodium administration, analgesia score using a visual analog scale, recovery time, and cardiopulmonary function in the different groups were assessed and compared. Group T showed significantly fewer counts of additional drug administration and a significantly higher analgesia score. Tramadol may provide adequate analgesia with minimal cardiopulmonary changes in calves during general anesthesia.