A randomized clinical trial of analgesia in children with acute abdominal pain

Objective: To evaluate the effects of intravenous morphine on pain reduction, physical examination, and diagnostic accuracy in children with acute abdominal pain. Methods: A randomized, double-blind, placebo-controlled clinical trial was conducted at an emergency department of a tertiary care children's hospital. Children aged 5-18 years with abdominal pain of 5 days' duration, pain score greater than or equal to5 on a 0-10 visual analog scale, and need for surgical evaluation were eligible. Following the initial assessment, patients were randomized to receive either 0.1 mg/kg morphine or an equal volume of saline. The pediatric emergency medicine physician and surgical consultant independently recorded the areas of tenderness to palpation and percussion, and their diagnoses before the study medication and 15 to 30 minutes later. Results: Sixty patients were enrolled, and 29 received morphine and 31 received saline. The demographic characteristics between the two groups were similar. The median reduction of pain score between the two study groups was 2 (95% CI = 1 to 4; p = 0.002). There was no significant change in the areas of tenderness in both study groups. Children with surgical conditions had persistent tenderness to palpation and/or percussion. There was no significant change in the diagnostic accuracy between the study groups and between the physician groups. All patients requiring laparotomy were identified and no significant complication was noted in the morphine group. Conclusions: Intravenous morphine provides significant pain reduction to children with acute abdominal pain without adversely affecting the examination, and morphine does not affect the ability to identify children with surgical conditions.