NONDEPOLARIZING NEUROMUSCULAR BLOCKING-DRUGS AND TRAIN-OF-4 FADE

The aim of this study was to examine differences in prejunctional effe cts of different relaxants by measuring the train-of-four (TOF) fade d uring the onset and recovery of neuramuscular block. The relaxants stu died were atracurium (225 mu g.kg(-1)), mivacurium (65 mu g.kg(-1) roc uronium (300 mu g.kg(-1) and vecuronium (40 mu g.kg(-1) The TOF ratios were measured al approximate heights of T-1 (first response in the TO F) of 90, 75, 50, and 25%. The TOF fade (as shown by lower TOF ratios) increased with a decrease in the T-1 during onset of neuromuscular bl ock. Although there was a slightly greater fade with atracurium and ro curonium during the onset of block, the differences among the relaxant s were insignificant. It is concluded that the relative prejunctional effects of these relaxants are similar