Respiratory status and diuresis following treatment with dexamethasone.

The effect of dexamethasone therapy on fluid balance, lung function and requirement for respiratory support has been assessed. Ten premature infants were studied, they had a median gestational age of 28 weeks. None of the infants had any improvement in the respiratory status for 48 h prior to commencing dexamethasone. Fluid balance, pulmonary function and requirement for respiratory support were measured 12 h prior to and for 36 h after receiving dexamethasone. There were no significant changes in fluid input over the study period, but urine output increased significantly after 12 h of dexamethasone therapy (P < 0.02). Compliance of the respiratory system only significantly improved after 36 h of dexamethasone therapy (P < 0.03), this was associated with a significant change in the inspired oxygen concentration (P < 0.05). We conclude that the improvement in respiratory status resulting from dexamethasone therapy is preceded by a diuresis.