IRCT20260428069197N1 IRCT 2026-06-28 Hamedan University of Medical Sciences Comparison of Local Lidocaine Infiltration, Intramuscular Morphine, and Placebo for Postoperative Pain Control After Percutaneous Nephrolithotomy (PCNL): A Double-Blind Randomized Controlled Trial Comparison of Local Lidocaine Infiltration, Intramuscular Morphine, and Placebo for Postoperative Pain Control After Percutaneous Nephrolithotomy (PCNL): A Double-Blind Randomized Controlled Trial 2026-05-22 anticipated 60 Recruiting https://irct.ir/trial/90172 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: To generate the random allocation sequence, SPSS version 26 was used. First, under the Transform menu, Random Number Generators was selected, and the Uniform method was set with a fixed seed of 20260321. Then, using the Compute Variable command, a uniform random variable ranging from 0 to 1 was created. After sorting cases by this random variable, blocks of size 6 were formed. Within each block of 6, 2 patients were randomly assigned to group A (local lidocaine), 2 to group B (intramuscular morphine), and 2 to group C (placebo). The final sequence consisted of a list of group codes (A, B, C) for 60 patients (20 blocks of 6). This sequence was printed on paper and placed into sequentially numbered, opaque, sealed envelopes. A nurse who was not involved in patient assessment opened the envelopes in numerical order and, based on the code inside, prepared the study drug or placebo in identical syringes. Neither the patient nor the outcome assessor was aware of the group code. No stratification was used, Blinding description: In this double‑blind trial, the participants (patients), the outcome assessor (anesthesiology resident) , and the data analyst were blinded to group allocation. Patients were unaware of the intervention they received. Study medications (lidocaine, morphine, and normal saline) were prepared by a nurse who was not involved in patient assessment, using identical syringes labeled only with a group code (A, B, or C). The surgeon (principal investigator) could not be blinded to the nature of the intervention because of the different routes of administration (local injection in groups A and C versus intramuscular injection in group B). However, he was also unaware of the syringe content in groups A and C (both injected locally). The anesthesiology resident who assessed pain using the Visual Analogue Scale (VAS) at 6, 12, 24, and 48 hours postoperatively had no knowledge of group assignment. Likewise, the data analyst received data coded by group letter (A, B, or C) only, with no information about the actual intervention, ensuring blinding during the analysis. No Data Safety and Monitoring Committee was involved in this study. 3 Calculus of kidney (Nephrolithiasis). Intervention 1: Control group: Infiltration of 20 mL of normal saline 0.9% (sodium chloride 0.9%), Caspian Tamin Pharmaceutical Company, administered locally (15 mL deep around the nephrostomy tract and 5 mL subcutaneously at the incision site) immediately after surgery and before skin closure, single dose, plus standard analgesic regimen (IV acetaminophen 1 g every 6 hours and IV ketorolac 30 mg every 8 hours). Intervention 2: Intervention group 1 : Infiltration of 20 mL of 2% lidocaine (containing 4 mg/kg lidocaine hydrochloride), Alborz Darou Pharmaceutical Company, administered locally (15 mL deep around the nephrostomy tract and 5 mL subcutaneously at the incision site) immediately after surgery and before skin closure, single dose, plus standard analgesic regimen (IV acetaminophen 1 g every 6 hours and IV ketorolac 30 mg every 8 hours). Intervention 3: Intervention group 2 : Intramuscular injection of 5 mg morphine sulfate (1 mL of a 10 mg/mL ampoule), Temad Pharmaceutical Company, administered during surgery after stabilization of the patient's vital signs, single dose, plus standard analgesic regimen (IV acetaminophen 1 g every 6 hours and IV ketorolac 30 mg every 8 hours). No - There is not a plan to make this available Justification or reason for not sharing IPD is Individual raw data will not be published due to confidentiality and lack of prior plans for public sharing.