HEMODYNAMIC-EFFECTS OF INTRAVENOUS MORPHINE INFUSION IN VENTILATED PRETERM BABIES

Background: the importance of sedation and analgesia of newborn babies in intensive care is only now receiving recognition in many neonatal units. Objective: to evaluate the hemodynamic effects of morphine on C erebral Blood Flow velocities (CBFv), Cardiac dutput (GO), Stroke Volu me (SV), Mean Arterial Blood Pressure (MABP) and Heart Rate (HR) in ve ntilated preterm infants, before and during the infusion of a loading dose. Design: prospective, Open, non-randomized, before-after interven tion study with hemodynamic measurements made by Doppler ultrasound. S etting: neonatal Intensive Care Unit, Tertiary Care Center. Patients: sequential sample of 30 ventilated preterm newborns (gestational age ( GA) 29+/-2 wks, range 27-31, birth weight (BW) 1240+/-440 g, range 800 -1680). Intervention: each subject received an intravenous loading dos e of morphine (100mcg/Kg/h) for 2 h, followed by a continuous infusion of 25 mcg/kg/h. Measurements: the following Doppler parameters of the anterior cerebral artery were estimated: Peak systolic flow velocity (Vs), end-diastolic flow velocity (Vd), mean flow velocity (Vm) and Po urcelot' Resistance Index (RI). Measurements of CBFv, CO and SV (by Do ppler ultrasound), MABP and HR were made 30 min before (baseline value s) and at 15 (M15), 30 (M30), 60 (M60) and 120 min (M20), during the m orphine loading infusion. Statistical evaluation analysis of variance, significance was calculated by Student-Newman-Kenfeld test. Results: there were no statistically significant changes in the cerebral and ca rdiac Doppler parameters before or during the 120 min of morphine load ing infusion. There was a non-significant fall in MABP (MABP: Baseline value = 44+/-6 mmHg, M120 = 42+/-4 mmHg; reduction = 4%) and HR (HR = Baseline value = 148+/-12 beats/min., M120 = 140+/-16 beats/min.; red uction = 5%). Conclusions: a loading dose of morphine over 2 h did not have any significant effect on MABP or cerebral and cardiac hemodynam ics. No adverse effects were noted that could be attributed to morphin e therapy. (C) 1997 Elsevier Science Ireland Ltd.