Posttetanic potentiation and fade in the response to tetanic and train-of-four stimulation during succinylcholine-induced block.

TitlePosttetanic potentiation and fade in the response to tetanic and train-of-four stimulation during succinylcholine-induced block.
Publication TypeJournal Article
Year of Publication2004
AuthorsNaguib M, Lien CA, Aker J, Eliazo R
JournalAnesth Analg
Volume98
Issue6
Pagination1686-91, table of contents
Date Published2004 Jun
ISSN0003-2999
KeywordsAdult, Analysis of Variance, Confidence Intervals, Dose-Response Relationship, Drug, Female, Humans, Male, Myography, Nerve Block, Prospective Studies, Succinylcholine, Tetany
Abstract

UNLABELLED: We designed this study to confirm anecdotal observations that neuromuscular block after a single administration of succinylcholine is characterized by fade to train-of-four (TOF) or tetanic stimulation, as well as posttetanic potentiation. This prospective, randomized, 2-center observational study involved 100 patients. Patients were allocated to 1 of 5 groups and received 0.1, 0.3, 0.5, 0.75, or 1.0 mg/kg succinylcholine during propofol/fentanyl/nitrous oxide anesthesia. Neuromuscular function was monitored by TOF using mechanomyography. At 10%-20% spontaneous recovery of the first twitch of TOF, the mode of stimulation was changed from TOF to 1-Hz single-twitch stimulation followed by a tetanic stimulus (50 Hz) for 5 s. Three seconds later, the single twitch (1 Hz) was applied again for approximately 30 s followed by TOF stimulation until full recovery of the TOF response. Succinylcholine-induced neuromuscular block had the following characteristics: 1) twitch augmentation before twitch depression, which was seen more frequently in patients given smaller doses (0.1 and 0.3 mg/kg) than in those given larger doses (0.5-1.0 mg/kg); 2) TOF fade during onset and recovery of the block; 3) tetanic fade; and 4) and posttetanic potentiation. Posttetanic potentiation was related to the pretetanic twitch height but was not related to the dose of succinylcholine administered. Some characteristics of Phase II block were detectable during onset and recovery from doses of succinylcholine as small as 0.30 mg/kg. Posttetanic potentiation and fade in response to train-of-four and tetanic stimuli are characteristics of neuromuscular block after bolus administration of different doses of succinylcholine.

IMPLICATIONS: Posttetanic potentiation and fade in response to train-of-four and tetanic stimuli are characteristics of neuromuscular block after bolus administration of different doses of succinylcholine. We also conclude that some characteristics of a Phase II block are evident from an initial dose (i.e., as small as 0.3 mg/kg) of succinylcholine.

Alternate JournalAnesth. Analg.
PubMed ID15155329