title: Effect of tetanic stimulation on subsequent train-of-four responses at various levels of vecuronium-induced neuromuscular block.
abstract: Tetanic stimulation influences subsequent neuromuscular responses. In addition, the tetanus-induced changes in neuromuscular responses differ according to the level of neuromuscular block at which tetanic stimulation is delivered. We studied the tetanus-induced effect on subsequent train-of-four (TOF) responses at various levels of vecuronium-induced neuromuscular block in 45 anaesthetized patients. Tetanic stimulation was applied when a twitch height of T1 returned to 25%, 50% and 75% of its control twitch height (T0) (groups 1, 2 and 3, respectively) after administration of vecuronium 0.1 mg kg-1. Maximum post-tetanic percentage increases in TOF responses in groups 1, 2 and 3 were 257 (SD 119)%, 107 (75)% and 68 (54)% for T1/T0 (P < 0.001 for group 1 vs 2; P < 0.001 for group 1 vs 3) and 535 (259)%, 421 (213)% and 292 (171)% for T4/T1 (P < 0.01 for group 1 vs 3), respectively. Durations of post-tetanic increases in TOF responses in groups 1, 2, and 3 were 52 (19) s, 37 (14) s and 32 (13) s for T1/T0 (P < 0.05 for group 1 vs 2; P < 0.01 for group 1 vs 3) and 53 (17) s, 46 (15) s and 35 (12) s for T4/T1 (P < 0.05 for group 1 vs 3), respectively. These data suggest that the tetanus-induced effect on subsequent TOF is more apparent and lasts longer at greater degrees than at lesser degrees of neuromuscular block.
authors.affiliation: Department of Anaesthesiology and Critical Care Medicine, Faculty of Medicine, Tokyo Medical and Dental University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Saitoh
authors.forename: A
authors.initials: A
authors.lastname: Masuda
authors.forename: H
authors.initials: H
authors.lastname: Toyooka
authors.forename: K
authors.initials: K
authors.lastname: Amaha
mesh_terms: D000328:Adult; D000768:Anesthesia, General; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D009469:Neuromuscular Junction / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors; D014673:Vecuronium Bromide / Q000494:pharmacology*
chemical_list: D014673:Vecuronium Bromide