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Enhancement of pressor response to ephedrine following clonidine medication
Author(s) -
TANAKA M.,
NISHIKAWA T.
Publication year - 1996
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.1365-2044.1996.tb07697.x
Subject(s) - clonidine , ephedrine , medicine , premedication , anesthesia , blood pressure , catecholamine , heart rate
Summary We studied pressor responses and changes in plasma catecholamine concentrations following two consecutive doses of ephedrine 0.1 mg.kg ‐1 with (n = 20) and without (n = 20) clonidine 5 μg.kg ‐1 premedication in patients presenting for a variety of major surgical procedures under general anaesthesia. Arterial blood pressure and heart rate were measured at 1 min intervals for 10 min, and plasma catecholamines were measured before and 3 min after each dose of ephedrine. Mean blood pressure changes from the baseline values were greater in the clonidine than in the control group 3–8 min and 4–9 min following the first and the second doses of ephedrine, respectively (p < 0.05). Plasma catecholamine concentrations tended to be lower in the clonidine group throughout the study. The augmented pressor response to ephedrine in clonidine‐treated patients can be attributed to enhanced cardiovascular response rather than clonidine‐induced accumulation and subsequent increased release of catecholamine.