Suppressive effect of nitrous oxide on motor evoked potentials can be reversed by train stimulation in rabbits under ketamine/fentanyl anaesthesia, but not with additional propofol
T. Sakamoto et al., Suppressive effect of nitrous oxide on motor evoked potentials can be reversed by train stimulation in rabbits under ketamine/fentanyl anaesthesia, but not with additional propofol, BR J ANAEST, 86(3), 2001, pp. 395-402
Citations number
27
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Aneshtesia & Intensive Care","Medical Research Diagnosis & Treatment
The effect of nitrous oxide on myogenic motor evoked potentials (MEPs) afte
r multipulse stimulation is controversial. We investigated the effects of p
ropofol in this paradigm. MEPs were elicited electrically by a single pulse
and by trains of three and five pulses in rabbits anaesthetized with ketam
ine and fentanyl. Nitrous oxide 30-70% was given and MEPs were recorded. Af
ter washout of nitrous oxide, propofol was given as a bolus of 10 mg kg(-1)
followed by 0.8 (n=9) or 1.6 mg kg(-1) min(-1) (n=8) as a continuous infus
ion. Nitrous oxide was then readministered and MEPs were recorded. Without
propofol, nitrous oxide significantly reduced the amplitude of MEPs dose-de
pendently, but this effect was reversed by multipulse stimulation. Administ
ration of low-dose propofol enhanced nitrous oxide-induced suppression, and
this effect was reversed by five-pulse stimulation. However, high-dose pro
pofol produced a greater increase in suppression, such that even five-pulse
stimulation did not overcome the suppression. The results suggest that the
degree of reversal of nitrous oxide-induced MEP suppression produced by mu
ltipulse stimulation is affected by the administration of propofol.