The relation between the serum trough concentration of paracetamol and pain reduction in preterm and term neonates: a retrospective observational study

Abstract

Abstract Background Measuring concentrations of paracetamol could be a strategy to better understand the concentration-response profile for pain treatment in preterm and term neonates. It is not known if the serum trough concentration of paracetamol at steady state conditions is associated with a decrease in pain in this population. Low trough concentration could result in inadequate pain relief, like end-of-dose pain. Aim The aim of this study was to determine the association between the serum trough concentration of paracetamol and pain reduction in preterm and term neonates. Method In this retrospective observational study a hospital database was used to select neonates who were treated with paracetamol intravenously or rectally for at least 48 hours. Linear regression was performed to determine if serum trough concentration of paracetamol at steady state conditions was a predictor for pain reduction. Pain reduction was defined as the difference between COMFORTneo scores before start and after the fifth dose of paracetamol. Results 21 neonates were included for determining the association between serum trough concentration paracetamol and pain reduction. The median (IQR) of serum trough concentration of paracetamol after the fifth dose was 4.5 mg/L (2.7–8.5 mg/L). At steady state conditions the serum trough concentration of paracetamol was not a significant predictor of pain reduction in preterm and term neonates (p = 0.79 for preterm neonates and p = 0.49 for term neonates). Conclusion No association was found between the serum trough concentration of paracetamol at steady state conditions and pain reduction in preterm and term neonates.