Retrospective study of short-term complications associated with early morphine use in intubated premature infants

Relieving neonatal pain is essential for the management of premature infants. Morphine is the most frequently used analgesic in neonatal intensive care. Here we report the relationship between early morphine infusion and the composite outcome of intraventricular hemorrhage and/or death in intubated premature infants. Infants (gestational age ≤ 32 weeks and birth weight < 1,500 g) intubated on admission were retrospectively evaluated in a large tertiary neonatal intensive care unit. Modified log-Poisson regression with robust variance estimator and Cox regression was applied to adjust the relative risk for infants' outcomes. Of 420 premature infants, 230 (54.7%) received continuous morphine infusion in the first 72 h. Of these, 153 were < 28 gestational weeks; of the 190 patients who did not receive morphine, 63 were < 28 gestational weeks. The analysis revealed that infants < 28 gestational weeks who received morphine were significantly associated with an increased risk for IVH and/or death [adjusted relative risk (aRR) 1.37, 95% confidence interval (CI) 1.1-1.71)], and mortality (aRR 1.83, 95% CI 1.17-2.89). Moreover, in infants < 28 gestational weeks, survival was low in those infants who were exposed to morphine infusion in the first 72 h (hazard ratio 2.11; 95% CI 1.19-3.73). Early morphine infusion is associated with an increased risk for IVH and/or death; however, further studies are required to verify our findings.