Lingen, R.A. van

morphine infant study concentration neonate paracetamol group effect children score procedure patient pain scores analgesia preterm acetaminophen pharmacokinetic value administration range assessment metabolite response result infusion lingen clearance adult vacuum extraction rectal serum pediatr chapter table method pain score placebo outcome van lingen ra pain assessment child development vacuum difference anand birth trial pretenn figure extraction arch dis child nurse rectally metabolism model preterm infants preterm neonates phannacokinetic 10 days 24 hours morphine infusion plasma pretenn infants blood morphine administration management reference level change bodyweight placebo group distribution condition period postnatal age urine pain management pharmacodynamic newborn hospital