Oral naproxen but not oral paracetamol reduces the need for rescue analgesic after adenoidectomy in children.

BACKGROUND

Our aim was to show the efficacy of naproxen and paracetamol with and without pethidine on pain and nausea and vomiting after adenoidectomy. The primary outcome was the requirement of rescue analgesic for post-operative pain and the secondary outcome was post-operative nausea and vomiting (PONV).

METHODS

A randomized, double-blind, placebo-controlled study design was used. Thirty minutes before anaesthesia induction, patients (n= 180) received either a single oral dose analgesic (naproxen 10 mg/kg or paracetamol 20 mg/kg) or a placebo. Half of the children received pethidine 1 mg/kg intravenously (i.v.) at the induction of anaesthesia. Post-operative pain was evaluated using an objective behavioural pain scale (OPS 0-9) and rescue medication, i.v. fentanyl 1 mug/kg, was administered if the child suffered from moderate or severe pain (OPS > or = 4).

RESULTS

When pethidine was not used, 83% of the children in the naproxen group vs. 97% in the other two groups required rescue fentanyl (P < 0.05). The use of pethidine reduced the incidence of fentanyl requirement by 30% and the number of fentanyl doses by 50% (P < 0.001). It also equalized the effects of naproxen, paracetamol and the placebo making the pain model invalid for this kind of study. The drawback associated with better analgesia was a doubling of the incidence of PONV (P < 0.001).

CONCLUSIONS

Oral naproxen (10 mg/kg), but not oral paracetamol (20 mg/kg), reduces the need for rescue analgesic after adenoidectomy in children. The sensitivity of the pain model is crucial for these types of studies.