Oxycodone vs placebo in children with undifferentiated abdominal pain: a randomized, double-blind clinical trial of the effect of analgesia on diagnostic accuracy.

BACKGROUND

Analgesics for children with acute abdominal pain are often withheld for fear that they might mask physical examination findings and thus might be unsafe. This viewpoint has been challenged recently.

OBJECTIVE

To evaluate the effects of buccal oxycodone on pain relief, physical examination findings, diagnostic accuracy, and final clinical outcomes in children with acute abdominal pain.

DESIGN

Prospective, randomized, double-blind, and placebo-controlled trial between December 2001 and November 2003.

SETTING

University teaching hospital in Finland. Patients A total of 104 children aged 4 to 15 years with abdominal pain of less than 7 days' duration were screened, and 63 children with pain scores of 5 or higher on a 10-cm visual analog scale were eligible for the trial. Intervention Children were randomized to receive buccally either 0.1 mg/kg(-1) of oxycodone hydrochloride (n = 32) or the same volume of normal saline (n = 31). The same surgeon described the physical findings and indicated a provisional diagnosis and a provisional disposition before the children received the study medication and at 1 hour and 3.5 hours after initial dosing. Pain scores were recorded at baseline and every 30 minutes for 3.5 hours after the first study drug administration.

MAIN OUTCOME MEASURES

Pain intensity difference, presence or absence of abdominal guarding, and diagnostic accuracy.

RESULTS

The demographic characteristics, initial pain scores, and physical signs and symptoms were similar between the 2 groups. Both study drugs were associated with decreasing pain scores. The summed pain intensity difference over 7 observations was significantly greater in the oxycodone group, 22 +/- 18 cm, than in the placebo group, 9 +/- 12 cm (mean difference 13 cm, with a 95% confidence interval of 2-24 cm; P = .04). The diagnostic accuracy increased from 72% to 88% in the oxycodone group and remained at 84% in the placebo group after study drug administration. Laparotomy was performed in 17 patients in the oxycodone group and in 14 patients in the placebo group. Four patients without appendicitis underwent exploratory laparotomy in each group. One patient in the placebo group was initially diagnosed as having nonspecific abdominal pain, but at 14 hours, she was operated on for appendiceal perforation.

CONCLUSIONS

Early administration of buccal oxycodone provides a significant pain relief to children with acute abdominal pain, without adversely altering the clinical signs or obscuring the surgical diagnosis.