Investigating the Effect of Xylapy cream 5% on Postoperative Sore Throat in Adults Following General Anesthesia with a Laryngeal Mask Airway: A Double-Blind Clinical Trial Study"

Investigating the Effect of Xylapy cream 5% on Postoperative Sore Throat in Adults Following General Anesthesia with a Laryngeal Mask Airway

A phase 2-3, randomized, double-blind, parallel-group, controlled clinical trial involving 300 patients. Randomization will be performed using the rand function of Excel software.

Anesthesia candidates referred to Firoozgar and Hasheminejad hospitals in Tehran will be included in the study and randomly assigned to intervention and control groups. This study will be conducted in a double-blind manner so that the outcome assessor and analyst will be blind to the type of intervention.

Inclusion Criteria: Adult patients of both genders, aged 18 to 65 years, classified as ASA (American Society of Anesthesiologists) physical status I and II, who are candidates for surgery lasting 1 to 3 hours under general anesthesia with a laryngeal mask airway (LMA). Exclusion Criteria: Known hypersensitivity to local anesthetics (LA); more than two attempts required for LMA insertion; patients undergoing head and neck surgeries involving the airway; airway injuries; preoperative pharyngeal pain; congenital oral anomalies; loose or artificial dentures; anticipated difficult airway.

Intervention: Zylapril 5% cream (2.5% lidocaine + 2.5% prilocaine, Tehran Chemi) applied to the pharyngeal mask cuff. Control: No anesthetic administered. The anesthesia protocol (midazolam, fentanyl, lidocaine, propofol, isoflurane), mask size/pressure, placement attempts (max 2), and extubation time will be the same for everyone. Patients are initially hospitalized in the recovery room for one hour after surgery and examined for sore throats once during this time and once after hospitalization in the ward .

Postoperative cough; Postoperative voice change; Sore throat; Hypoxia;

In this study, the block random allocation method will be employed. First, the randomization sequence will be generated before the study commences and patient recruitment, ensuring that the initial blocks containing 4 parts are created by considering all possible allocation scenarios for the intervention group (I) and control group (C) within each block (such as I-I-C-C, I-C-I-C, etc.). Then, the created blocks will be randomly numbered using the Excel RAND function. After sorting the numbers from smallest to largest, the order of block selection will be determined, and we will proceed to select the blocks. Block selection will continue until the required sample size is reached. To conceal the allocation, the treatments will be coded and placed in sealed envelopes. These envelopes will be opened only after the patient is registered in the study. In each block, 4 allocations (2 cases in the intervention group and 2 cases in the control group) will occur, and this process will continue until the target sample size is met.

Since the treatment methods used are unnamed and will be identified by specific codes, the outcome assessor and analyst will remain blinded to the type of intervention.