TIME-COURSE OF ACTION AND ENDOTRACHEAL INTUBATING CONDITIONS OF ORG-9487, A NEW SHORT-ACTING STEROIDAL MUSCLE-RELAXANT - A COMPARISON WITH SUCCINYLCHOLINE

In a randomized study, we evaluated lag time (time from the end of inj ection of muscle relaxant until the first depression of the train-of-f our response [TOF]), onset time (time from the end of injection of mus cle relaxant until the maximum depression of the first twitch of the T OF [T1]), neuromuscular block, and endotracheal intubating conditions at 1 min after 1 mg/kg succinylcholine (n = 15) and 1.5 mg/kg Org 9487 (n = 30). Two minutes after administration of Org 9487, 15 of the 30 patients received neostigmine for reversal. Recovery of neuromuscular block after succinylcholine, Org 9487 without and Org 9487 with neosti gmine were compared using the time until T1 was 90% for the succinylch oline group, and the time until TOF was 70% for the Org 9487 groups. N euromuscular transmission was monitored mechanomyographically. Onset t ime was similar (67 [20] and 83 [38] s for succinylcholine and Org 948 7, respectively) and endotracheal intubating conditions were also simi lar after both muscle relaxants. Times until clinically sufficient rec overy of neuromuscular block induced by succinylcholine (time until T1 = 90%:10.6 [3.31 min) and Org 9487 with neostigmine (time until TOF = 70%: 11.6 [1.4] min) were not different. In contrast, in the Org 9487 without neostigmine group, more time was required until complete reco very (24.1 [6.2] min) (P < 0.05). In conclusion, Org 9487 is a muscle relaxant suitable for endotracheal intubation and short-lasting interv entions.