Dose-response relationships for edrophonium antagonism of mivacurium-induced neuromuscular block during N2O-enflurane-alfentanil anaesthesia.
The purpose of this study was to determine the dose-response relationships for edrophonium antagonism of mivacurium-induced neuromuscular block. Seventy-five ASA I or II adults were given mivarcurium 0.15 mg x kg(-1) followed by an infusion (7 micrograms x kg(-1) x min(-1) during alfentanil-propofol-N2O-enflurane anaesthesia. Train-of-four stimulation (TOF) was applied to the ulnar nerve every 20 sec and the response of the adductor policis was recorded (Relaxograph NMT-100, Datex, Helsinki, Finland). Mivacurium infusion was modified at five-minute intervals in order to keep the height of the first twitch in TOF(T1) at 5% of its control value. At the end of surgery, edrophonium (0.0, 0.125, 0.25, 0.5, or 1.0 mg x kg(-1) combined glycopyrrolate (0.0, 0.0012, 0.0025, 0.005, or 0.01 mg x kg(-1) were administered by random allocation. Edrophonium doses of 0.25, 0.5 and 1.0 mg x kg(-1) were different from placebo with regard to time to attain a TOF ratio (fourth twitch in TOF/T1) = 0.7 (13.8 +/- 4.5, 11.1 +/- 3.5, 11.4 +/- 3.0 vs 19.7 +/- 4.7 min P< 0.05). Doses of 0.5 and 1.0 mg x kg(-1) permitted faster recovery time of T1 from 10 to 95% (T10-95) than did placebo (7.5 +/- 3.8, 8.9 +/- 3.5 vs 14.5 +/- 5.0 min P<0.05). Edrophonium 0.5 mg x kg(-1) was different from placebo with regard to recovery time of T1 from 25 to 75% (T25-75) (3.3 +/- 2.0 vs 6.7 +/- 2.0 min P<0.05). Only edrophonium 0.5 mg x kg(-1) provided faster recovery than placebo with regard to all three indices. It is concluded that edrophonium 0.5 + glycopyrrolate 0.005 mg x kg(-1) allow the fastest recovery from a mivacurium-induced block during enflurane-N2O anaesthesia.
Marcotte
J
J
Department of Anaesthesia, Maisonneuve-Rosemont Hospital, University of Montreal, Quebec.
Drolet
P
P
Perreault
L
L
Girard
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D015760:Alfentanil / Q000008:administration & dosage; D000758:Anesthesia; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004491:Edrophonium / Q000494:pharmacology*; D004737:Enflurane / Q000008:administration & dosage; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007546:Isoquinolines / Q000037:antagonists & inhibitors*; D008297:Male; D008875:Middle Aged; D000077590:Mivacurium; D009469:Neuromuscular Junction / Q000187:drug effects*; D003473:Neuromuscular Nondepolarizing Agents / Q000037:antagonists & inhibitors*; D009609:Nitrous Oxide / Q000008:administration & dosage
D002800:Cholinesterase Inhibitors; D007546:Isoquinolines; D003473:Neuromuscular Nondepolarizing Agents; D015760:Alfentanil; D004491:Edrophonium; D000077590:Mivacurium; D004737:Enflurane; D009609:Nitrous Oxide