Many factors influence the adequacy and distribution of systemic blood flow during extracorporeal circulation.1 The liberation of endogenous vasoactive substances may alter the character of the perfusion or modify the function of various organs. Even during perfusions with conditions maintained within "physiologic" limits, there may be alterations in blood catecholamine levels.2
Another vasoactive amine which may be liberated from intracellular sites by a variety of interventions is histamine. This substance has many pharmacologic properties which might alter the status of an animal during cardiopulmonary bypass.3 It may increase vascular permeability, modify ganglionic transmission in the sympathetic nervous system, alter regional flow by relaxation of vascular smooth muscle, or affect the heart directly. In addition it may cause bronchiolar constriction; this could have a bearing on the pulmonary complications that may follow cardiopulmonary bypass.
Because of these relevant possibilities, it seemed desirable to study plasma histamine levels during
COOPER T, JELLINEK M, WILLMAN VL, SCHWEISS JF, HANLON CR. Plasma Histamine During Cardiopulmonary Bypass in Man. Arch Surg. 1963;86(1):138-142. doi:10.1001/archsurg.1963.01310070140018