Abstract

Background: The administration of analgesics to patients with acute abdominal pain due to acute appendicitis is controversial. A study was undertaken to assess the analgesic effect of morphine in patients with acute appendicitis.

Methods: A randomised double-blind clinical trial was conducted in Sina hospital, a general teaching hospital, from January 2004 to March 2005. Patients scheduled for appendectomy were randomised to receive 0.1 mg/kg morphine sulfate or saline (0.9%) to a maximum dose of 10 mg over a 5 min period. Patients were examined by surgeons not involved in their care before and after drug administration and their pain intensity and signs were recorded at each visit. The physicians were also asked to indicate their own treatment plan. The main outcome measures were pain intensity using a visual analogue scale (VAS) and signs of acute appendicitis. A favourable reduction in VAS score was defined as a change of >13 mm.

Results: Of the 71 patients enrolled in the study, 35 were allocated to receive morphine and 36 to receive placebo. One patient left the hospital before receiving morphine. No significant differences were seen between the two groups with regard to age, sex and initial VAS score. A more favourable change in VAS score was reported in the morphine group with a significantly greater reduction in the median VAS score than in the placebo group. Morphine administration did not cause significant changes in patients’ signs or in the physicians’ plans or diagnoses. No adverse events were seen in either group.

Conclusion: Morphine can reduce pain in patients with acute appendicitis without affecting diagnostic accuracy.

Trial registration number: NCT00477061.