EFFECTS OF CONTINUOUS INFUSION OF FENTANYL CITRATE (FC) ON CSF AND CEREBROVASCULAR PROSTANOID CONCENTRATIONS IN NEWBORN PIGLETS. † 1370

FC is most commonly used for routine, ongoing analgesia and sedation in newborns exposed to repeated pain and prolonged stress in the NICU. The hypothesis that FC exert effects on cerebrovascular prostaglandins was determined in 14 newborn pigs (1-3 days old), treated with either: a loading dose of FC (30 μg/kg i.v.) over 15 minutes, followed by a continuous infusion of FC (10 μg/kg/hr) for 6 hours (n=6); or 5% dextrose at 6 mg/kg/minute (placebo group, n=8). CSF from the cisterna magna was collected at 0 (pre-dose) and 6 hrs, and blood from the sagittal sinus vein was collected at 0 (pre-dose), 0.5, 2, 4 & 6 hrs during infusion for measurements of PGE₂, 6-keto PGF_1α and TXB₂, by enzyme immunoassay. Our data show that in the FC group, CSF levels of PGE₂ fell by 75% (p<0.001), and CSF levels of 6-ketoPGF_1α and TXB₂ increased by 150% and 80%, respectively, at 6 hrs of infusion. In addition, sagittal sinus plasma 6-keto PGF_1α and TXB₂ increased substantially at 0.5 hr and 2 hrs, with negligible effect on PGE₂ levels. Values are mean±SD(pg/ml). *p<0.01, **p<0.001. We speculate that such marked changes in the levels of cerebrovascular prostanoids may contribute to adverse neurophysiologic effects, in newborns treated with FC.Table

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