Haemodynamics of intravenous paracetamol in neonates

Introduction: Reports on the haemodynamics of intravenous (iv) paracetamol in adult intensive care were recently published. We therefore wanted to explore the haemodynamics of iv paracetamol in neonates. Methods: Retrospective, pooled analysis of heart rate (bpm) and blood pressure (mean, systolic, diastolic) observations collected during iv paracetamol pharmacokinetic studies in neonates. Heart rate and blood pressure were recorded just before and 30, 60, 120, 180, 240, 300 and 360 min after iv paracetamol (paired, ANOVA). Clinical characteristics in hypotensive (mean mmHg < gestational age, weeks) cases were compared with controls (Mann-Whitney U test). Results: Based on observations in 72 neonates, heart rate decreased from 145 (SD 20) to 138 (21), 141 (20), 137 (20), 137 (22), 140 (20), 139 (20) and 140 (21) bpm (paired p < 0.05, ANOVA p = 0.36). There were no changes in systolic and diastolic pressure, but mean arterial pressure decreased from 46 (7) to 43 (8) mmHg at 60 min (paired p < 0.05, ANOVA p = 0.75). Eight neonates developed hypotension. These patients had lower pre-administration arterial pressure (38 vs 47 mmHg, p < 0.05). Conclusions: In a setting of open label administration to alleviate (procedural) pain, haemodynamic effects of iv paracetamol in neonates remained modest. We suggest considering impaired haemodynamics to be a relative contra-indication for iv paracetamol in neonates.