A COMPARISON OF EDROPHONIUM AND NEOSTIGMINE FOR THE REVERSAL OF MIVACURIUM-INDUCED NEUROMUSCULAR BLOCKADE IN SHEEP

The rate of reversal of neuromuscular block was compared in 36 sheep r eceiving either edrophonium (500 mu g kg(-1)) and atropine (80 mu g kg (-1)), neostigmine (50 mu g kg(-1)) and atropine (80 mu g kg(-1)) or s aline (10 ml), using the train of four count (TO4C) recorded at n. fac ialis - m. levator nasolabialis. Neuromuscular block was produced with mivacurium (200 mu g kg(-1)) followed later by a single incremental d ose of 70 mu g kg(-1). Antagonists or saline were given when spontaneo us recovery from the incremental dose (TO4C = 1) had begun. The TO4C i ncreased from 1 to 4 in all animals, in all treatment groups within 10 minutes of reversal. The TO4C was 4 in all animals five minutes after edrophonium, and seven minutes after neostigmine; differences were no t statistically significant. The TO4C was significantly higher with ed rophonium two and three minutes after antagonism compared with saline. The data show that spontaneous recovery from mivacurium is rapid in s heep, although reversal is accelerated by anticholinesterase drugs.