Plasma Concentration of Epinephrine and Norepinephrine in Hemorrhagic and Anaphylactic Shock

Abstract

A fluorometric method was used to quantitate plasma epinephrine and norepinephrine during hemorrhagic and anaphylactic shock in healthy adult dogs anesthetized with pentobarbital. Arterial plasma was analyzed before and after hemorrhage in four dogs. Loss of approximately 18% of blood volume through rapid arterial bleeding caused no remarkable change in pressor amines. Loss of approximately one-third of the total blood volume decreased the mean arterial pressure by a range of 56–81% and invariably caused increased concentration of plasma pressor amines. The average concentration of epinephrine increased from 1.0 to 7.8 µg/1. of plasma, and that of norepinephrine increased from 2.5 to 3.6 µg. Additional bleeding caused further increase of plasma pressor amines. Seven dogs were given egg white intravenously to sensitize them. Subsequently, whenever a severe reaction (hypotension, bradycardia and respiratory depression) resulted from intravenous administration of egg white, venous plasma pressor amines increased. The average concentration of epinephrine increased from 0.7 to 7.7 µg/1. of plasma; norepinephrine increased in three dogs but remained unchanged or decreased in the remaining animals. Without a preceding ‘shock’ reaction, change in concentration of epinephrine-like substance was unremarkable. Intravenous administration of 1 mg of histamine base produced hypotension and usually slight increase of plasma pressor amines.