560 Effects of Morphine on General Movements of Preterm Infants

Abstract

Background: The influence of morphine on the developing central nervous system (CNS) of preterm infants is not fully known. Concern for neurological side effects has lead to hesitancy in using morphine within NICUs. Analysis of general movements (GMs) is a method to evaluate the influence of medication on cerebral function. Objective: To investigate the influence of morphine treatment on cerebral function of preterm infants by analyzing the quality of their GMs. Method: Prospective cohort study on preterm infants receiving continuous morphine (10 µg/ kg/h) for at least 24h. We assessed GM-quality before, during and after morphine treatment. To evaluate subtle differences in movement quality, we also determined a motor optimality score (OS, range 8-18) of the GMs. Finally, we determined the relationship between GMs and various clinical factors that might confound our findings. Results: Twenty-nine preterm infants (GA 31 [25.6- 35.7] weeks, birthweight 1525 [630-3000] grams, median[range]) were studied. After morphine was started, GM-quality and OS did not change. During morphine treatment OS improved, with median OS increasing from 9 to 10 (p< 0.05). After morphine therapy GM-quality and OS improved further, median OS increasing to 12 (p < 0.01). Duration of morphine treatment did not influence GM-quality or OS. GM-quality correlated positively to postnatal age (r=0.444, p< 0.01) and negatively to respiratory support (r= -0.490, p< 0.01). Conclusion: Morphine treatment did not impair quality of movements in preterm infants. This study indicates that morphine treatment has no direct adverse influence on the CNS and can be used safely in preterm infants.