Effects of pretreatment with propofol on bupivacaine-induced systemic toxicities in rats

AIM: To evaluate the effect of propofol pretreatment on central nervous system and cardiac toxicities induced by bupivacaine in rats. METHODS: Twenty Sprague Dawley rats were assigned to two groups (n=10 each group). Animals in the control group received 10 ml/kg of saline injection, whereas rats in the propofol pretreatment group received 100 mg/kg (10 ml/kg) of propofol injection IP 30 min before IV infusion of bupivacaine. ECG was continuously monitored. The femoral artery was cannulated for measuring arterial blood pressure and drawing blood samples. The femoral vein was cannulated for the infusion of bupivacaine. After the basic parameters (arterial blood pressure, heart rate and arterial blood gases) were recorded, 5 g/L bupivacaine was infused IV at a rate of 2 mg/(kg·min) to all animals in both groups until asystole. The time of bupivacaine-produced convulsions, QRS prolongation in ECG (arrhythmia) and asystole were recorded. Cumulative dose of bupivacaine was then calculated at the corresponding timepoints. RESULTS: Cumulative doses of bupivacaine that produced convulsions, arrhythmia and asystole in animals pretreated with propofol were (8.9±2.1) mg/kg, (10.5±2.8) mg/kg and (28.0±4.9) mg/kg, respectively, significantly higher than in saline-treated rats (7.2±2.1) mg/kg, (8.5±2.5) mg/kg and (22.4±3.4) mg/kg, respectively (P<0.05). CONCLUSION: Pretreatment with propofol reduces central nervous system and cardiac toxicities of bupivacaine.