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Dose‐response relationships for infusions of Althesin or methohexitone
Author(s) -
SEAR J. W.,
PHILLIPS K. C.,
ANDREWS C. J. H.,
PRYSROBERTS C.
Publication year - 1983
Publication title -
anaesthesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.839
H-Index - 117
eISSN - 1365-2044
pISSN - 0003-2409
DOI - 10.1111/j.1365-2044.1983.tb12021.x
Subject(s) - medicine , anesthesia , diazepam , nitrous oxide , methohexital , morphine , propofol
Summary A technique is described for the determination of equipotent rates of infusion of intravenous hypnotic agents. Two end points have been defined; the rates needed to suppress the initial response to the surgical incision in 50% (ED 50 ) and 95% (ED 95 ) of patients receiving continuous infusion anaesthesia to supplement 67% nitrous oxide in oxygen. For patients aged 20–60 years, and premedicated with morphine 0.15 mg/kg intramuscularly, the ED 50 values for Althesin (as alphaxalone) and methohexitone by infusion were 13.7 and 48.8 μg/kg/minute respectively. The ED 95 values were 18.1 and 75.9 μg/kg/minute. For patients of a similar age premedicated with diazepam 10 mg orally, the ED 50 values for Althesin and methohexitone were 18.5 and 66.0 μg/kgjminute respectively; while the ED 95 values were 24.2 and 80.8μg/kg/minute.