Nebulized Fentanyl for Relief of Abdominal Pain

OBJECTIVE: To compare the efficacies of nebulized vs. intravenous fentanyl for the relief of abdominal pain. METHODS: This randomized, double-blind, double-placebo-controlled study compared nebulized and intravenous fentanyl (1.5 micro g/kg). Group I received intravenous fentanyl and nebulized saline. Group II received nebulized fentanyl and intravenous saline. Pain scores were measured at baseline and at 15 and 30 minutes after the study drug, using a 100-mm visual analog scale. Thirty minutes after the study drug, the subjects were offered rescue medication. The groups were compared for changes in pain scores at 30 minutes (primary outcome, t-test), changes in pain scores at 15 minutes (t-test), and need for rescue medication (Fisher's exact test). Significance was defined as p < 0.05. RESULTS: Fifty subjects (24 group I, 26 group II) were enrolled. The groups were similar with respect to mean baseline pain (72 mm group I, 74 mm group II) and demographics. A statistically significant difference in changes in pain scores at 15 minutes favoring group I (25 mm vs. 10 mm, p = 0.005) was not evident by 30 minutes (25 mm vs. 16 mm, p = 0.24). The groups were not different with respect to need for rescue medication (50% in group I compared with 69% in group II, p = 0.25). CONCLUSIONS: Nebulized fentanyl provides comparable analgesia to that of intravenous fentanyl.