British Journal of Anaesthesia, Vol 83, Issue 4 590-595, Copyright © 1999 by The Board of Management and Trustees of the British Journal of Anaesthesia
OHG. Wilder-Smith, P. A. Ravussin, L. A. Decosterd, P. A. Despland and B. Bissonnette
We have studied the effects of midazolam premedication on multiple
anaesthetic end-points (hypnotic, loss of verbal contact (LVC); motor,
dropping an infusion flex or bag (DF); analgesic, loss of reaction to
painful stimulation (LRP); and EEG, attainment of burst suppression (BUR))
during induction by slow thiopental infusion at a rate of 55 mg kg-1 h-1.
Patients received midazolam 0.05 mg kg-1 i.v. (group TM, n = 12) or no
midazolam (group T0, n = 13). ED50 and ED95 values and group medians for
times and doses at the end-points were measured. Midazolam premedication
reduced significantly thiopental ED50 and ED95 values at all end-points
(exception for ED95 for BUR). Potentiation was greatest for the motor
end-point (dropping the infusion bag (DF)) (ED95 +52%, ED50 +23%, median
+39%), and smallest for painful stimulation (LRP) (median +18%; ED50 +13%).
For LRP and DF, premedication was associated with significant, non-parallel
increases in the slope of the thiopental dose-response curves, resulting in
marked potency ratio changes from ED50 to ED95 (LRP +31%, DF +29%). There
were no such increases for LVC or BUR. The interaction between midazolam
and thiopental varied with the anaesthetic end-point and may also depend on
the dose of thiopental. Our data suggest that the mechanism of interaction
between midazolam premedication and thiopental was different for motor
effects or analgesia (DF, LRP) compared with hypnotic effects or cortical
depression (LVC, BUR), in agreement with the different central nervous
system substrates underlying these distinct anaesthetic end-points.
CLINICAL INVESTIGATIONS
Midazolam premedication and thiopental induction of anaesthesia: interactions at multiple end-points
Department of Anaesthesiology, Lausanne University Hospital (CHUV), Lausanne, Switzerland
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
M. Naguib, A. H. Samarkandi, M. A. Moniem, E. E.-D. Mansour, A. A. Alshaer, H. A. Al-Ayyaf, A. Fadin, and S. W. Alharby The Effects of Melatonin Premedication on Propofol and Thiopental Induction Dose-Response Curves: A Prospective, Randomized, Double-Blind Study Anesth. Analg., December 1, 2006; 103(6): 1448 - 1452. [Abstract] [Full Text] [PDF] |
||||
