Pleural effusions, water balance mediators and the influence of lisinopril after completion Fontan procedures

Objective: To investigate whether the duration of pleural drainage after Fontan completion operations can be influenced by postoperative lisinopril administration or can be related to water balance hormone levels. Methods: In a prospective trial 21 patients scheduled for total cavopulmonary connection were randomized into two groups, with group I receiving lisinopril postoperatively, and group II receiving no angiotensin converting enzyme inhibitor. Plasma levels of antidiuretic hormone, renin and aldosteron were analyzed preoperatively and at four-time points postoperatively. Groups were comparable for age, preoperative saturation and pulmonary pressure, cardiopulmonary bypass time, cross-clamp time and preoperative hormone levels. Results: Mean duration of pleural drainage was comparable for both groups (group I: 9.6 ± 8 days vs group II: 10 ± 7 days; p = 0.78). The hormone profiles in each group changed significantly at 1 and 24 h postoperatively compared to preoperative values (p ≪ 0.05), with no significant differences between the treatment groups. The duration of pleural drainage correlated significantly with hormone levels at 24 h postoperatively, and with longer bypass times. At multivariate analysis only aldosteron and antidiuretic hormone level at 24 h came out as factors reaching significance for prolonged pleural drainage. Conclusions: The Fontan completion induces significant changes in the levels of antidiuretic hormone, aldosteron and renin. Prolonged drainage correlates significantly with elevated levels of aldosteron, renin and antidiuretic hormone postoperatively, and with longer bypass time, but is not influenced by lisinopril. The eventual adjunct therapy with aldosteron antagonists warrants further study.