Early treated hypotension and outcome in very low birth weight infants

Early hypotension is a common problem among preterm infants. Studies have shown conflicting data regarding the definition of hypotension, the way to treat it and the correlation to outcome.

To investigate the risk factors for developing hypotension and its relations to short- and long-term outcomes.

Medical charts of all surviving very low birth weight infants were retrospectively reviewed during a 4-year period. The data of infants suffering from early hypotension and needed treatment were compared with those of a control group with 'normal' blood pressure. In addition, medical charts were reviewed for neurodevelopment outcome.

The study and control groups comprised 109 infants each. The mean blood pressures were 24.1 +/- 3.2 and 30.3 +/- 4.3 mm Hg in the study and control groups (p < 0.0001). No significant perinatal variables were found to predict hypotension. Bronchopulmonary dysplasia and retinopathy of prematurity were related to treated hypotension. Logistic regression analysis found that neonatal treated hypotension was related to periventricular leukomalacia, with an odds ratio of 2.61 (95% CI 1.0-7.12), p = 0.049. Intraventricular hemorrhages grades 2-4 were found to be related to lower mean blood pressure, with an odds ratio of 1.3 (95% CI 1.12-1.51), p < 0.01. Major long-term neurological disability was found by regression analysis to be related to periventricular leukomalacia and treated hypotension, with odds ratios of 63.1 (95% CI 13.3-299, p < 0.001) and 5.4 (95% CI 1.29-22.7, p = 0.01).

This study supports the hypothesis that early provision of antihypotensive therapy is related to intraventricular hemorrhage, periventricular leukomalacia and major neurodevelopment impairment.