COMPARISON OF PROPOFOL WITH THIOPENTONE FOR TREATMENT OF BUPIVACAINE-INDUCED SEIZURES IN RATS

Thirty Sprague-Dawley rats were paralysed with pancuronium and their lungs ventilated mechanically with 70% nitrous oxide and 0.5% halothane in oxygen. Bupivacaine 2 mg kg-1 min-1 was infused continuously i. v. until the animals died. At the onset of seizures, animals were given an iv. bolus of propofol 1 mg kg-1 (n = 10), thiopentone 2 mg kg-1 (n = 10) or lipid vehicle (n = 10). Administration of propofol or thiopentone was repeated each time seizures restarted and lipid vehicle administrations were repeated at 2-min intervals until the electroencephalogram became isoelectric. All animals developed seizures, arrhythmias, iso-electric EEG and asystole. Administration of lipid vehicle induced no obvious changes in ongoing epileptiform activity. The initial doses of thiopentone and of propofol stopped epileptiform activity in all animals, usually within 6 s after administration. The seizure-free period after the initial administration of thiopentone and of propofol lasted, on average, 0.98 min and 1. 72 min, respectively. We conclude that propofol may have value in treating seizures induced by bupivacaine.