THE EFFECT OF HYPOTHERMIC CARDIOPULMONARY BYPASS ON PLASMA ADRENOMEDULLIN IN ADULT CARDIAC SURGICAL PATIENTS

Cardiopulmonary bypass (CPB) can evoke a systemic inflammatory respons e, which is accompanied by an increase in plasma cytokines that may st imulate the production of adrenomedullin (AM), a potent vasodilator pe ptide. This study was undertaken to investigate whether CPB influenced plasma AM concentration in 10 patients undergoing cardiac surgical pr ocedures. We found that the plasma AM concentration increased signific antly after the commencement of CPB, with the greatest increase observ ed at weaning from bypass (P < 0.01). After CPB, plasma AM concentrati on declined but still exceeded baseline significantly 24 h postoperati vely. The increase in the plasma AM concentration at weaning from CPB correlated significantly with aortic cross-clamp time (I = 0.74, P < 0 .05). The authors conclude that the secretion of AM into circulation i s augmented by CPB in patients undergoing cardiac surgery, which sugge sts a possible role of AM in cardiovascular regulation during and afte r surgery with CPB.