The effect of inotropes on morbidity and mortality in preterm infants with low systemic or organ blood flow

Low systemic blood flow is common in extremely premature infants and has been associated with brain and intestinal injury, death and developmental impairment. It is unclear what is the best strategy to prevent or treat this. The usual strategy for supporting the cardiovascular system of the preterm infant is to treat infants with low blood pressure with agents (inotropes) aimed at increasing blood pressure. However, many of infants with low blood flow have normal blood pressure. One trial was found that examined the effect of inotropes in infants with low systemic blood flow. The trial found that many infants failed to respond to the two commonly used inotropes (dobutamine and dopamine) and neither was better at improving outcomes of very preterm babies. Further research is needed to determine the best strategy for preventing or treating low systemic or organ blood flow in these very immature babies.

Authors' conclusions: 

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.

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Background: 

Low systemic blood flow (SBF) is common in extremely premature infants in the first day after birth and has been associated with peri / intraventricular haemorrhage (PIVH), necrotising enterocolitis (NEC), mortality and developmental impairment.

Objectives: 

To determine the effect of specific inotropes on morbidity and mortality in preterm infants with low systemic blood flow

Search strategy: 

Updated searches were made of CENTRAL (The Cochrane Library, Issue 1, 2010), MEDLINE (1966 to May 2010), EMBASE (1980 to May 2010) and CINAHL (1982 to May 2010), supplemented by searches of abstracts of conference proceedings, citations of reviews and expert informants.

Selection criteria: 

Random and quasi-random controlled trials of inotropes enrolling preterm infants with low systemic or organ blood flow in the neonatal period.

Data collection and analysis: 

Independent assessment of trial eligibility, quality and data extraction by each review author.

Main results: 

No new studies were found in updated search. No studies that compared an inotrope to no treatment in preterm infants with low SBF were found. One study compared dobutamine versus dopamine in preterm infants with low SVC flow. The study was of adequate methodology. No significant difference was reported in mortality to discharge, PIVH, grade 3 or 4 PIVH or NEC. At three years, there was no significant difference in cerebral palsy, deafness, developmental quotient > 2 sd below norm or combined disability. Surviving infants treated with dobutamine had a significantly higher development quotient. There was no significant difference in death or disability at the latest time reported (RR 0.95, 95% CI 0.66, 1.38). For secondary outcomes, there was no significant difference in periventricular leucomalacia, renal impairment, pulmonary haemorrhage, retinopathy of prematurity or CLD at 36 weeks. There was no significant difference in treatment failure. Dobutamine produced a significantly greater increase in SVC flow at the highest dose reached, whereas dopamine produced a significantly greater increase in mean BP.