RANDOMIZED TRIAL OF LONG-TERM DIURETIC THERAPY FOR INFANTS WITH OXYGEN-DEPENDENT BRONCHOPULMONARY DYSPLASIA

Study objective: To determine whether long-term oral diuretic therapy would improve the pulmonary function of preterm infants with bronchopu lmonary dysplasia. Design: Randomized, double-blind, placebo-controlle d study. Setting: Level III intensive care nursery. Intervention: We r andomly selected 43 stable patients with oxygen-dependent bronchopulmo nary dysplasia to receive either orally administered spironolactone an d chlorothiazide or placebo. These drugs were continued until the pati ents no longer required supplemental oxygen. Both groups received furo semide as needed. Measurements and results: Each infant had pulmonary function tests at study entry, 4 weeks after study entry, 1 week and 8 weeks after being weaned to room air and off study drugs, and at 1 ye ar of corrected age. Pulmonary function tests included dynamic pulmona ry compliance, airway resistance, thoracic gas volume, and maximal exp iratory flow at functional residual capacity; most of the infants had functional residual capacity measured. Between the first and second pu lmonary function tests (while the infants were receiving diuretic or p lacebo), the infants in the diuretic group had a significant improveme nt in dynamic pulmonary compliance (46%; p <0.001) and airway resistan ce (31%; p <0.05); there were no changes in compliance or resistance i n the placebo group. Although patients in both the diuretic and the pl acebo groups required progressively less supplemental oxygen, by 4 wee ks after study entry the patients in the diuretic group needed less su pplemental oxygen than did those in the placebo group (p <0.01). There were no significant differences in results of serial pulmonary functi on tests in either group of ter discontinuation of diuretic therapy. D espite the significant differences in pulmonary function between the t wo groups, there was no significant difference between them in the tot al number of days that supplemental oxygen was required. Significantly more infantsin the placebo group received more than 10 doses of furos emide on an asneeded basis. Conclusions: Long-term diuretic therapy in stable infants with oxygen-dependent bronchopulmonary dyslasia, after extubation, improves their pulmonary function and decreases their fra ctional inspired oxygen requirement, but does not decrease the number of days that they require supplemental oxygen. The improvement in pulm onary function associated with diuretic therapy is not maintained afte r treatment is discontinued.