Abstract 1377

Background. Elevated levels of antidiuretic hormone (ADH) have been demonstrated in premature infants with BPD. Dexamethasone treatment improves pulmonary function, and is frequently associated with a significant increase in diuresis and a decrease in weight gain.

Specific Aim. To determine whether diuresis is primarily the results of ADH inhibition potentially induced by dexamethasone treatment.

Subjects and Methods. Plasma ADH (reference laboratory values for healthy prematures: 7-14 ng/ml) and osmolality, serum sodium and potassium concentrations, 12-hour urine output and osmolality were measured before and after (3 and 7 days, respectively) the start of dexamethasone (0.5 mg/kg/day IM or IV) in 8 prematures (birth weight 802±141 g; gestation 26±2 weeks) with BPD age 1-2 months.

Results. All premature infants required mechanical ventilation at the start of therapy, and 4 were extubated during the steroid course. None of the infants were receiving diuretics or cardiac drugs during the study period. Mean ± SD values were as follows: (Table)

Table 1 No caption available
Full size table

Conclusions. Our data indicate that ventilated premature infants with BPD have functionally unmodified ADH levels after 3 and 7 days of dexamethasone. Nevertheless, this does not significantly correlate with the concurrent post-steroid reduction in weight gain.