Efficacy of continuous low-dose human atrial natriuretic peptide given from the beginning of cardiopulmonary bypass for thoracic aortic surgery

Purpose. Cardiac surgery performed under cardio pulmonary bypass (CPB) causes abnormalities of the renin-angiotensin-aldosterone system, resulting in decreased urine output and an accumulation of water in the third space. We studied the efficacy of continuous low-dose human atrial natriuretic peptide (hANP) in patients undergoing thoracic aortic surgery. Methods. We divided 40 patients undergoing thoracic aortic surgery into two groups: the hANP group, which received 0.02 mu g/kg per minute of hANP and the non-hANP group, which did not. The hemodynamics, urine output, intensive care unit (ICU) and hospital stay, bleeding volume, homologous blood transfusion volume, furosemide dose, corrected KCl volume, and postoperative respiratory, hepatic, and renal function were compared in the two groups. Results. The urine output during CPB and from CPB weaning to return to ICU was significantly better in the hANP group. The bleeding volume, homologous blood transfusion volume, furosemide dose, and corrected KCl volume were all significantly less in the hANP group. Conclusions. These findings support the consensus that hANP exerts its diuretic effects to their full potential when administered continuously at low doses during thoracic aortic surgery. We found it to be effective for postoperative hemostasis and for preventing ischemic reperfusion injury.