Randomized, blind trial of dopamine versus dobutamine for treatment of hypotension in preterm infants with respiratory distress syndrome. Left ventricular contractility in extremely premature infants in the first day and response to inotropes. Response to dobutamine and dopamine in the hypotensive very preterm infant. Assessment of therapy for arterial hypotension in critically ill preterm infants. Randomized trial comparing dopamine and dobutamine in preterm infants. The haemodynamic effects of dopamine and volume expansion in sick preterm infants. Impact on blood pressure and intestinal perfusion of dobutamine or dopamine in hypotensive preterm infants. Randomised controlled trial of plasma protein fraction versus dopamine in hypotensive very low birthweight infants. The cardiovascular effects of dopamine in the severely asphyxiated neonate.
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. The aim was to assess myocardial contractility in infants born <30 wk gestation developing low systemic blood flow (SBF) in the first day, and the effect of dobutamine versus dopamine. Superior vena cava (SVC) flow was used as a measure of SBF at 3, 10, and 24 h (n = 106). Infants with low SVC flow randomized to dopamine or dobutamine. Myocardial contractility was determined by the relationship between left ventricular (LV) mean velocity of circumferential fiber shortening (mVcfs) and wall stress. Infants who developed low SVC flow had significantly worse myocardial contractility at 3 h, but not 10 h. At 24 h, low-flow infants had lower than expected mVcfs for any given LV stress. In 37 infants randomized to inotrope, there was no significant difference in contractility at 10 microg/kg/min. At 20 microg/kg/min (n = 21), dopamine increased whereas dobutamine decreased LV stress. Infants on dobutamine had significantly lower than expected mVcfs for any given LV stress compared with infants on dopamine. Contractility was not improved by either inotrope at either dose. In conclusion, infants developing low SVC flow in the first day have worse myocardial contractility at 3 h. Neither inotrope increased contractility, but dopamine increased LV stress at 20 microg/kg/min. A randomised double blind study was designed to evaluate haemodynamic response to dobutamine and dopamine in 20 hypotensive preterm infants of less than 32 weeks' gestation. Neonates initially received dopamine or dobutamine 5 micrograms/kg/min. If mean arterial pressure (MAP) remained below 31 mm Hg, the infusion rate was increased in increments of 5 micrograms/kg/min. If 20 micrograms/kg/min of the initial drug failed to achieve a MAP above 30 mm Hg, it was discontinued and the other drug was administered at the same infusion rate. Left ventricular output (LVO) was measured by pulsed Doppler echocardiography. Mean (SE) MAP increased significantly from 24.4 (1.0) to 32.0 (1.4) mm Hg at a median dobutamine dosage of 20 micrograms/kg/min and from 25.6 (1.2) to 37.7 (1.5) mm Hg at a median dopamine dosage of 12.5 micrograms/kg/min. The percentage LVO increase was +21 (7)% with dobutamine compared with -14 (8)% with dopamine. Dobutamine failed to increase MAP above 30 mm Hg in six infants out of 10, whereas dopamine succeeded in all 10 infants. Six switches from dobutamine to dopamine were thus performed, providing a rise in MAP (29.2 (0.5) to 41.2 (2.0) mm Hg) and drop in LVO (356 (40) to 263 (36) ml/kg/min). These data indicate that dopamine is more effective than dobutamine in raising and maintaining MAP above 30 mm Hg; however dopamine does not increase LVO. The aim of this paper is to assess the efficacy of albumin and dopamine compared with albumin and dobutamine in treating hypotension in preterm newborn infants (PNI). A randomized, open-label, prospective, cross-over study, was designed on 66 PNI whose weights were between 1,000 to 1,500 g, and persistent hypotension, defined as a mean arterial pressure (MAP) of < 30 mmHg. Infants were randomly allocated to two groups and received a 5% albumin infusion at a dosage of 20 mL/kg, in 30 min. Thereafter, one group received dopamine and the other dobutamine at doses of 5 microg/kg/min. If there was not an increase in MAP values > 30 mmHg, the infusions were increased every 20 min by 2.5 microg/kg/min, up to a maximum of 10 microg/kg/min. Treatment failure was considered when there was no pressure response within 2 hr after the infusion started; then patients were changed to the other catecholamine. Statistical analysis was done with student's t-test, x2, and Fisher's exact probability test. There were no differences between groups in initial features. Overall, MAP was normalized with dopamine in 29 of 33 infants and with dobutamine in 25 of 33 infants (p > 0.05). The initial dosage of 5 microg/kg/min, was adequate in 22 infants treated with dopamine and in 13 treated with dobutamine (p < 0.05). The change from dopamine to dobutamine was successful in three out of four patients, while changing from dobutamine to dopamine was adequate in seven out of eight patients. Dopamine is recognized as the drug of choice to treat hypotension in PNI. Since our results showed only small differences in responses, it is proposed that dobutamine is also as efficacious and useful as dopamine. The aim of this study was to compare the efficacy of two inotropic infusions in treating low BP in preterm neonates. Forty infants with median gestational age 27 weeks (range 23-33) were studied. At trial entry the infants, who all had a systolic BP < 40 mmHg despite receiving a colloid infusion, were randomized to receive either a dopamine or dobutamine infusion. The infusions were commenced at a rate of 5 micrograms/kg per min and, if necessary, this was increased over the 3 h study period to 15 micrograms/kg per min. There was no significant difference in the gestational or postnatal age or baseline BP of the 20 infants who received dopamine and those 20 who received dobutamine. Three hours after commencing the infusions, although there was no difference in the rate of inotrope infusion between the two groups, the infants who received dopamine had a significantly higher systolic BP, a median of 39 mmHg (range 30-58) compared to a median of 34 mmHg (range 21-46) in the dobutamine group, P < 0.05. In addition, 10 infants who received dopamine, but only 3 who received dobutamine, had a systolic BP > 40 mmHg (P < 0.05). We conclude that dopamine rather than dobutamine infusion is more efficacious in improving the BP of preterm neonates. To determine the haemodynamic effects of dopamine and volume expansion in preterm neonates. Effect parameters were mean arterial blood pressure (MABP), left ventricular output (LVO) and global cerebral blood flow (CBF).
                In a randomised, clinical control trial 36 preterm neonates were randomised to receive either dopamine 5 microg/kg per min, volume expansion with albumin 20% 15 ml/kg or no treatment. Parameters were measured before and 2 h after initiation of treatment.
                Dopamine was effective in increasing MABP; both treatments increased LVO, whereas no significant difference between the treatment groups and the control group could be demonstrated with regard to CBF.
                No effect on global cerebral blood flow could be demonstrated in this study, despite significant effects on systemic circulatory parameters. However, the variance on the measurement of cerebral blood flow indicates that a small but clinically significant effect may have been overlooked. In a prospective study hemodynamic effects of dobutamine or dopamine (10 micrograms/kg/min) were investigated in 20 preterm infants who had protracted arterial hypotension refractory to volume therapy. Doppler ultrasonography of the superior mesenteric artery (SMA) was applied to verify intestinal perfusion and blood pressure was recorded in parallel. Mean arterial pressure (MAP) raised significantly in both groups (from 31.0 +/- 6.8 to 37.7 +/- 9.8 mm Hg during dobutamine and from 27.7 +/- 3.6 to 36.0 +/- 9.3 mm Hg during dopamine). Mean blood flow velocity increased from 25.8 +/- 13.5 to 31.5 +/- 16 cm/s with dobutamine and from 16.3 +/- 5.0 to 19.0 +/- 6.0 cm/s with dopamine (significant for dobutamine). Vascular resistance of SMA (indicated by resistance index; RI) decreased from 0.81 +/- 0.07 to 0.74 +/- 0.11 for dobutamine and from 0.89 +/- 0.06 to 0.79 +/- 0.07 for dopamine (significant for both groups). These data indicate that in the dose tested here both catecholamines are equally effective in raising MAP and lead to a significant increase of intestinal perfusion. Thus, a negative impact on mesenteric blood supply, predisposing to necrotizing enterocolitis, is not probable. Around 20% of very low birthweight infants admitted to a neonatal intensive care unit become hypotensive within 24 hours of their admission. Standard treatment is either expansion of the circulating volume by the infusion of plasma protein fraction or by using dopamine to improve cardiac function. The purpose of this study was to investigate by a randomised controlled trial which was the most appropriate treatment. Thirty nine infants were randomised to receive either plasma protein fraction or dopamine as first line treatment if they became hypotensive within 24 hours of admission to the neonatal intensive care unit. Seventeen of 19 (89%) infants responded to dopamine, whereas only 9/20 (45%) responded to plasma protein fraction. The median dose of dopamine needed to increase the blood pressure to at least the 10th centile was 7.5 micrograms/kg/min and was infused for a median duration of 18 hours. These observations suggest that dopamine should be used earlier in the treatment of these infants than has previously been recommended. The cardiovascular effects of dopamine were evaluated in 14 severely asphyxiated neonates. After a period of stabilization, either dopamine 2.5 micrograms/kg/minute or placebo was infused in a randomized double-blind protocol. In seven dopamine-treated infants, echocardiographically determined shortening fraction and mean velocity of circumferential fiber shortening increased when compared to preinfusion values (P less than 0.05). There was no significant change in these echo indices of cardiac function in the placebo-treated group. Systolic blood pressure rose in the dopamine group when compared to predopamine infusion values and to the postinfusion values of the placebo group (P less than 0.001 and 0.025, respectively). Diastolic blood pressure increased to a small degree in the dopamine group. There was no significant change in heart rate or echocardiographically measured systolic time intervals. Low doses of dopamine increase cardiac performance and raise systolic blood pressure in the severely asphyxiated neonate.
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.