Randomized controlled trial of morphine in elderly patients with acute abdominal pain

BACKGROUND: The objective of this study was to determine the clinically important change in diagnostic accuracy and physical examination in the morphine vs. placebo group. METHODS: Subjects were randomized in a 1:1 ratio to receive a single dose intravenous morphine or placebo in a blinded fashion. Primary outcome measure was to determine if there was a clinically important change in diagnostic accuracy and physical examination in the morphine vs. placebo group. RESULTS: 80 subjects (39 were assigned to morphine and 41 to placebo) were included in the final analysis. Clinically important diagnostic accuracy rate was found to be 80% in the morphine group (31/39) and 78% in the placebo group (32/41), with a difference rate of 2% (95% CI -7% to 13%, p=0.9802. There was a statistically significant change in abdominal rigidity finding (15%) in morphine group in all of the abdominal physical examinations findings; however there was no change in placebo group (0%). The difference between two groups was also statistically significant (95% CI 2.3% to 30.5%, p= 0.031). CONCLUSION: Administration of opioid analgesia is safe and does not seem to impair clinical diagnostic accuracy in elderly patients with acute undifferentiated abdominal pain. Nevermore, opioids may change the physical examination findings such as abdominal rigidity.