Relationship of post-tetanic count and train-of-four response during intense neuromuscular blockade caused by atracurium.
Atracurium-induced intense neuromuscular blockade was evaluated in 60 randomly selected patients using the post-tetanic count (PTC) and train-of-four (TOF) methods. Thirty patients were anaesthetized with thiopentone, nitrous oxide and halothane, and 30 patients received thiopentone, nitrous oxide and fentanyl. In all patients, the response to post-tetanic single twitch stimulation appeared before the response to TOF stimulation, and a close correlation was found between the number of post-tetanic twitches (PTC) and the time interval between the PTC and the first detectable TOF response. A PTC of zero indicated that the time to first response to TOF stimulation was always more than 8 min. A PTC of 1 meant that the TOF response would appear in, on average, 9 min (95% confidence limits: 4-14 min). Halothane significantly prolonged the time from injection of atracurium to the first response to post-tetanic single twitch stimulation. It is concluded that the relationship between PTC and the time to first response to TOF nerve stimulation makes the PTC method a valuable supplement to TOF nerve stimulation for neuromuscular monitoring during clinical anaesthesia involving atracurium.
Bonsu
A K
AK
Department of Anaesthesia and Intensive Care, King Khalid University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia.
Viby-Mogensen
J
J
Fernando
P U
PU
Muchhal
K
K
Tamilarasan
A
A
Lambourne
A
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D001279:Atracurium / Q000494:pharmacology*; D004558:Electric Stimulation; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009119:Muscle Contraction / Q000187:drug effects; D009469:Neuromuscular Junction / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects*; D014459:Ulnar Nerve / Q000502:physiology
D001279:Atracurium