Abstract

Objectives: To compare dopamine versus dobutamine endocrine effects in hypotensive very low birthweight (VLBW) newborns.

Design: Non blinded randomized prospective trial.

Setting: Level III Neonatal intensive care unit.

Patients: Thirty-five hypotensive VLBW infants who did not respond to volume loading were alternatively assigned to receive dopamine or dobutamine.

Measurements: Haemodynamic parameters and serum TSH, T4, PRL, GH were assessed during the first 72 hours of treatment and the first 72 hours after withdrawal.

Results: Demographic and clinical data did not significantly differ between the two groups. Necessary cumulative and mean drug doses and maximum infusion to normalize blood pressure were significantly higher for dobutamine than dopamine. TSH, T4 and PRL suppression was observed in dopamine-treated newborns from 12 hours of treatment onward, while GH resulted significantly reduced only at 12 and 36 hours of treatment. TSH, T4 and PRL rebound was observed since the first day after dopamine interruption. On the contrary, dobutamine administration did not modify any hormonal profile and no rebound was observed after withdrawal.

Conclusion: Dopamine and dobutamine are both useful to improve systemic blood pressure, even if dopamine resulted more effective. Dopamine reduces serum TSH, T4 and PRL in VLBW newborns but such suppression is quickly reversed after withdrawal. Further researches are required to assess whether short term iatrogenic pituitary suppression has longer term consequences.