Acute late sepsis attenuates effects of a nondepolarizing neuromuscular blocker, rocuronium, by facilitation of endplate potential and enhancement of membrane excitability in vitro.
BACKGROUND
Sepsis attenuates the muscle-relaxing effects of nondepolarizing neuromuscular blockers. The authors investigated the effects of acute late sepsis on neuromuscular transmission and neuromuscular actions of rocuronium to clarify the mechanisms by which sepsis attenuates the effects of nondepolarizing neuromuscular blockers.


METHODS
Sepsis was induced by cecal ligation and puncture operation. Endplate potentials, acetylcholine potentials, and electrotonic potentials were recorded from the motor endplates of isolated diaphragms from acute late septic and nonseptic rats.


RESULTS
(1) Sepsis did not influence the effect of rocuronium to decrease endplate potential amplitude, which was increased by sepsis itself; (2) sepsis facilitated the effect of rocuronium to decrease quantal acetylcholine release, which was increased by sepsis itself; (3) sepsis did not influence the effect of rocuronium to decrease acetylcholine sensitivity, which was decreased by sepsis itself; (4) sepsis decreased critical depolarization, and rocuronium did not influence critical depolarization.


CONCLUSIONS
These results indicate that acute late sepsis facilitates endplate potentials and enhances excitability of the muscle membrane, indicated by a decrease of critical depolarization. It is thought that these elicit the sepsis-induced attenuation of the muscle-relaxing effects of rocuronium.
Niiya
Tomohisa
T
Department of Anesthesiology, Sapporo Medical University School of Medicine, Sapporo, Japan. niiya@pop12.odn.ne.jp
Narimatsu
Eichi
E
Namiki
Akiyoshi
A
D000208:Acute Disease; D000732:Androstanols / Q000494:pharmacology*; D000818:Animals; D004558:Electric Stimulation; D004594:Electrophysiology; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009045:Motor Endplate / Q000187:drug effects* / Q000503:physiopathology*; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D000077123:Rocuronium; D018805:Sepsis / Q000503:physiopathology*; D009435:Synaptic Transmission / Q000187:drug effects
D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D000077123:Rocuronium