Pediatric Analgesia After Cardiac Surgery; Morphine IV Versus Paracetamol IV After Cardiac Surgery in Neonates and Infants.

Congenital heart disease accounts for almost one third of all congenital anomalies. Surgical intervention is necessary in 55% within the first year of life and in 67% during the first three years of life.

Morphine is the drug of first choice worldwide for pain relief after major surgery in neonates and children. However, morphine can cause unwanted hemodynamic and respiratory reactions and therefore patients could potentially benefit from a non-opioid analgesic.

In a recent randomized controlled trial, intravenous (IV) paracetamol was compared with morphine as a primary analgesic drug in non-cardiac post-operative children up to 1 year. IV paracetamol was equally effective in pain relief, and no difference in rescue analgesics was shown between groups. The IV paracetamol group had a lower cumulative morphine dose the first 48 h after surgery and less adverse drug reactions.

Whether these results also apply to neonates and children after cardiac surgery is unclear. Pharmacokinetic (PK) parameters are assumed to be different in patients during and after cardiac surgery compared with non-cardiac surgery due to use of the cardiopulmonary bypass (CPB).

Hypothesis The investigators' hypothesis is that intermittent IV paracetamol is effective as the primary analgesic drug in post-cardiac surgery patients up to 3 years of age and that the use of IV paracetamol will reduce overall morphine requirements.