Randomized, blind trial of dopamine versus dobutamine for treatment of hypotension in preterm infants with respiratory distress syndrome.
To compare the efficacy of dopamine and dobutamine for the treatment of hypotension (mean arterial blood pressure, < or = 30 mm Hg) in preterm (< or = 34 weeks of gestation) infants with respiratory distress syndrome in the first 24 hours of life, we enrolled 63 hypotensive preterm infants in a randomized, blind trial. Inclusion criteria required an arterial catheter for measurement of mean arterial blood pressure, treatment with exogenous surfactant, and persistent hypotension after volume expansion with 20 ml/kg (packed erythrocytes if hematocrit < 0.40, 5% albumin if > or = 0.40). Intravenous study drug infusions were initiated at 5 micrograms/kg per minute and then increased in increments of 5 micrograms/kg per minute at 20-minute intervals until a mean arterial blood pressure > 30 mm Hg was attained and sustained for > or = 30 minutes (success) or a maximum rate of 20 micrograms/kg per minute was reached without resolution of hypotension (failure). The study groups at entry were comparable for birth weight, gestational age, postnatal age, gender, birth depression, hematocrit < 0.40, heart rate, oxygenation index, delivery route, maternal chorioamnionitis, and maternal magnesium or ritodrine therapy. No infants in the dopamine group had a treatment failure (0/31; 0%); (16%) of 32 infants failed to respond to dobutamine (p = 0.028). Success was attained at < or = 10 micrograms/kg per minute in 30 (97%) of 31 infants given dopamine and in 22 (69%) of 32 infants given dobutamine (p < 0.01). Among those treated successfully, the increase in mean arterial blood pressure was significantly higher in those given dopamine (mean, 11.3 vs 6.8 mm Hg; p = 0.003). We conclude that dopamine is more effective than dobutamine for the early treatment of hypotension in preterm infants with respiratory distress syndrome.
In preterm infants with low systemic blood flow, there is some evidence that dobutamine is better than dopamine at increasing and maintaining systemic blood flow. The only eligible trial did not demonstrate any consistent differences in clinical outcomes. However, this study was not sufficiently powered to prove or disprove effects on clinical outcomes. It is unclear what is the most effective strategy for improving the cardiovascular status of immature infants in the first day. Further trials are needed to determine effective strategies for preventing and improving low systemic and organ blood flow.