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

Citation
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
Journal title
BRITISH JOURNAL OF ANAESTHESIA
ISSN journal
0007-0912 → ACNP
Volume
86
Issue
3
Year of publication
2001
Pages
395 - 402
Database
ISI
SICI code
0007-0912(200103)86:3<395:SEONOO>2.0.ZU;2-M
Abstract
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.