Factors affecting magnitude and time course of neuromuscular block produced by suxamethonium.
This study was designed to identify factors that significantly alter the magnitude and duration of suxamethonium-induced neuromuscular block in patients with an apparently normal genotype for pseudocholinesterase. One hundred and fifty-six adults (ages 18-65 yr) were allocated to 13 subgroups. Patients in each subgroup received suxamethonium 50-2000 micrograms kg-1. The mechanographic response of the adductor pollicis brevis muscle to ulnar nerve stimulation was recorded. The ED50 was found to be 167 micrograms kg-1, ED90 was 316 micrograms kg-1 and ED95 was 392 micrograms kg-1. The duration of action (delta t) was in agreement with earlier published results. The magnitude of block was dose-related and decreased with increasing onset time (ton) and pseudocholinesterase activity (PChA). Neither age nor gender affected the degree of suxamethonium-induced block. Delta t was dose-related, decreased with increasing PChA, and was shorter for women. Age and ton had no effect on delta t.
Vanlinthout
L E
LE
Institute for Anesthesiology, University of Nijmegen, The Netherlands.
van Egmond
J
J
de Boo
T
T
Lerou
J G
JG
Wevers
R A
RA
Booij
L H
LH
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001835:Body Weight / Q000502:physiology; D002091:Butyrylcholinesterase / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block; D009469:Neuromuscular Junction / Q000187:drug effects*; D012727:Sex Characteristics; D013390:Succinylcholine; D013997:Time Factors
D002091:Butyrylcholinesterase; D013390:Succinylcholine