A Double Blind, Multi-arm Randomized Control Trial, for Efficacy of Intramuscular Diclofenac Versus Intravenous Morphine Versus Intravenous Paracetamol, in Renal Colic Emergency Department Pain Management

This will be a double blind RCT, where participants will be enrolled consecutively after meeting eligibility criteria and obtaining a written informed consent. They will be assign to one of the three study arms by computer generated randomization process. The study packets will be prepared by a dedicated nurse or pharmacist who will not a part of investigating team. Each Patients will receive one analgesic drug (active drug) and two placebos. Drugs will be given as one intramuscular injection and two intravenous solutions.

Pain score will be recorded using NRS at 0, 30, 60, and 90 minutes. Data will be collected on standard Data collection form. Each participant will receive analgesia from study packet which contains, one active drug and two placebos to be administer as one intramuscular and two intravenous solutions. At any given time every patient will receive one analgesia from either Diclofenac, Paracetamol or Morphine. If patient pain does not respond to initial treatments, at 30 minutes a rescue analgesia in form of morphine will be administered till patient is pain free or NRS<=2 or adverse event to morphine.

Based on the results of previous studies (1-3), proportion of patients achieving more than 50% pain reduction, is between 65-75% for diclofenac, morphine and paracetamol when compared with other drugs. In each group, 437 patients are required to detect a difference of 10% in primary outcome, in a superiority trial with power (1-beta) of 90% and significance level (alpha) of 5% in this study. Considering 15% extra, total sample size required in this superiority trial will be 1507 patients in total.

Data will be collected on a standard data recording form and it will be converted to electronic excel sheet hiding patient identifiable details. Continuous variables will be presented as mean with standard deviation (SD). Categorical variables will be calculated as proportions and presented with 95% Confidence interval (CI). Statistical analyses will be undertaken using Stata 12.0 (College Station, Texas).