Antidiuretic hormone and cardiovascular responses during and after coronary artery bypass surgery.

In order to evaluate correlations in changes of postoperative plasma antidiuretic hormone (ADH) concentrations and hemodynamic parameters, 23 patients undergoing coronary artery bypass surgery were observed. 6 patients required intraaortic balloon pumping (IABP) (group I), 8 patients did not require IABP or inotropic agent (group II), and 9 patients required inotropic agent (group III) for weaning from cardiopulmonary bypass (CPB). Soon after CPB mean arterial and pulse pressures were significantly less in group I compared to other groups. Plasma ADH concentrations were significantly higher in group I than in group II, and showed significant negative correlation with hemodynamic parameters. On the 2nd postoperative day, plasma ADH concentrations in group I were significantly higher than in the other two groups, but were not correlated with hemodynamic parameters. Thus, early after surgery high plasma ADH concentrations in the IABP group directly reflected hemodynamic derangement, while at later times ADH secretion was influenced mainly by postsurgical stress.