Objective: To study the effects of continuous morphine infusion on arterial blood pressure in ventilatedneonates.
Design: Blinded randomised placebo controlled trial.
Setting: Level III neonatal intensive care unit in two centres.
Patients: A total of 144 ventilated neonates. Inclusion criteria were postnatal age,3 days, ventilation,8 hours, and indwelling arterial line. Exclusion criteria were severe asphyxia, severe intraventricularhaemorrhage, major congenital anomalies, neuromuscular blockers.
Intervention: Arterial blood pressure was measured before the start and during the first 48 hours ofmasked infusion of drug (morphine/placebo; 100mg/kg+10mg/kg/h).
Outcome measures: Arterial blood pressure and blood pressure variability.
Results:There were no significant differences in overall mean arterial blood pressure between themorphine group (median (interquartile range) 36 mm Hg (6) and the placebo group (38 mm Hg (6)) (p =0.11). Although significantly more morphine treated patients (70%) showed hypotension than the placebogroup (47%) (p = 0.004), the use of volume expanders and vasopressor drugs was not significantlydifferent (morphine group, 44%; placebo group, 48%; p = 0.87), indicating the limited clinicalsignificance of this side effect. Blood pressure variability was not influenced by routine morphine analgesia(p = 0.81) or additional morphine (p = 0.80). Patients with and without intraventricular haemorrhageshowed no differences in blood pressure (Mann-Whitney U test 1953; p = 0.14) or incidence ofhypotension (x2test 1.16; df 1; p = 0.28).
Conclusions:Overall arterial blood pressure, use of inotropes, and blood pressure variability were notinfluenced by morphine infusion. Therefore the clinical impact of hypotension as a side effect of low dosemorphine treatment in neonates is negligible.

doi.org/10.1136/adc.2004.069831, hdl.handle.net/1765/56112
Archives of Disease in Childhood: an international peer-reviewed journal for health professionals and researchers covering conception to adolescence
Department of Pediatric Surgery

Simons, S., Roofthooft, D., van Dijk, M., Lingen, R., Duivenvoorden, H., van den Anker, J., & Tibboel, D. (2006). Morphine in ventilated neonates: Its effects on arterial blood pressure. Archives of Disease in Childhood: an international peer-reviewed journal for health professionals and researchers covering conception to adolescence, 91(1). doi:10.1136/adc.2004.069831