Comparing Intradermal Sterile Water with Intravenous Morphine in Reducing Pain in Patients with Renal Colic: A Double-Blind Randomized Clinical Trial.

Objective: The present study was conducted to investigate the effect of intradermal administration of sterile water compared to intravenous morphine on patients with renal colic.

Methods: This double-blind, randomized clinical trial study was conducted in 2017 to compare the therapeutic effects of intradermal sterile water with those of intravenous morphine on patients with renal colic presenting to the emergency departments (ED) of Imam Khomeini and Golestan Hospitals in Ahvaz, Iran. The first group received 0.5 ml of intradermal sterile water, and the second group 0.1mg/kg of intravenous morphine plus 0.5 ml of intradermal sterile water in the most painful area or the center of the painful area in the flank. The pain severity was measured using a visual analogue scale (VAS), and the medication side-effects were recorded at the beginning of the study and minutes 15, 30,45 and 60.

Results: A total of 94 patients were studied in two groups. The mean severity of pain was 2.97 ± 1.51 in the sterile water group and 2.34 ± 1.89 in the morphine group at minute 30 (P=0.042), 2.58 ± 1.43 in the sterile water group and 1 ± 1.23 in the morphine group at minute 45 (P<0.001), and 1.89 ± 1.7 in the sterile water group and 0.52 ± 0.79 in the morphine group at minute 60 (P<0.001).

Conclusion: Morphine reduces pain faster and more effectively than intradermal sterile water; nevertheless, treatment with intradermal sterile water can be used as an appropriate surrogate or adjunct therapy for pain control, particularly in special patients or in case of medication scarcity.