Epinephrine-containing test dose during beta-blockade.
Epinephrine is routinely used as a marker for intravascular injection during administration of regional anesthesia. The cardiovascular response of patients on beta-blockers to such a test dose has been reported to be unpredictable. We investigated this interaction by administering 15 micrograms of epinephrine intravenously to 6 healthy volunteers 39 to 48 years old before and after beta-blockade, accomplished by intravenous injection of propranolol, 0.04 mg/kg. Epinephrine administration caused a 20 +/- 4% (mean +/- SEM) increase in heart rate before beta-blockade but a 38 +/- 3% reduction after beta-blockade. The lowest heart rate recorded was 28 beats/min. We conclude that, in middle-aged beta-blocked men, intravenous injection of a standard epinephrine-containing test dose will predictably cause significant hypertension followed by marked bradycardia.
Department of Anesthesiology, Harborview Medical Center, University of Washington School of Medicine, Seattle 98104.
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Mackie
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D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000328:Adult; D000765:Anesthesia, Conduction / Q000379:methods*; D001794:Blood Pressure / Q000187:drug effects; D004347:Drug Interactions; D004837:Epinephrine / Q000008:administration & dosage; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D011433:Propranolol / Q000494:pharmacology; D013268:Stimulation, Chemical
D000319:Adrenergic beta-Antagonists; D011433:Propranolol; D004837:Epinephrine