The Impact of Saline Temperature and Local Anesthetic Adjuvants on Postoperative Shoulder Pain and Inflammatory Marker Levels Following Laparoscopic Cholecystectomy

This study will be a randomized, double-blind, controlled trial with a factorial design, consisting of six groups based on saline temperature and the presence of local anesthetic adjuvants:

Group A1: Room-temperature saline (25-30 ml/kg ) irrigation without local anesthetic.

Group A2: Room-temperature saline (25-30 ml/kg l) with local anesthetic ( 0.25% bupivacaine according to body weight).

Group B1: Warm saline (37°C, 25-30 ml/kg ) irrigation without local anesthetic. Group B2: Warm saline (37°C, 25-30 ml/kg) with local anesthetic (0.25% bupivacaine).

Group C1: No saline irrigation. Group C2: No saline irrigation but with local anesthetic (local anesthetic instillation at trocar sites).

Intervention: All of the patients will not premedicated . The anesthesia will be induced along with lidocaine 1 mg/kg, propofol 1.5 mg/kg, and rocuronium 0.6 mg/kg intravenous, and was maintained with sevoflurane (2-3%). The intraoperative and postoperative pain will be controlled with intravenous fentanyl 2-3 μg/kg. All the laparoscopic cholecystectomies (LCs) will be performed by the same team of experienced professionals. A pneumoperitoneum will be created by insufflating CO2 gas through a 10- mm trocar in the umbilicus, and will be maintained at 12 mmHg throughout the surgery. Prior to the surgery, all patients will be moved into a reverse Trendelenburg position with a left tilt (10°), and the LC will be conducted using the standard 4-port technique. After complete hemostasis, a drain insertion will be selectively performed only in cases with intraoperative bile leakage. The patients will then randomly divided into 6 groups Saline irrigation will be performed after the removal of the gallbladder but before the closure of the trocar incisions. Local anesthetic (bupivacaine: 0.25%) will be added to the saline solution in groups A2 and B2 or administered to the subdiaphragmatic area in the no-irrigation group (C2).

A standardized postoperative analgesic regimen will be consisting of 8 h interval regular IV ketorolac 30mg and Patient controlled analgesia (PCA) that will be started at the PACU and continued during the first 24 h postoperatively. PCA device will be used for all patients to deliver a continuous IV infusion of 0.3 mg/h of morphine and a bolus of 1 mg IV morphine with a 20 min lockout time.

Outcome Measures Primary Endpoint: Postoperative Shoulder Pain Intensity: VAS scores recorded at 6, 24, 48, and 72 hours postoperatively.

Secondary Endpoints: Postoperative Abdominal Pain): Patients will rate their abdominal pain intensity on a scale of 0 (no pain) to 10 (worst imaginable pain) using, Visual Analog Scale (VAS) at 6 ,12,18,24 and 48 hours. Total Postoperative Analgesic Consumption:,Total amount of opioid and non-opioid analgesics used in the first 72 hours.Time to First Rescue Analgesic: Time from the end of surgery to the first administration of rescue analgesics (e.g., opioid).Length of Postoperative Hospital Stay: Duration from the end of surgery to discharge.Patient Satisfaction with Pain Control: Patients will complete a satisfaction questionnaire during the first 72 hours. Incidence of Postoperative Shoulder Pain: Proportion of patients reporting shoulder pain during the first 72 hours.

Postoperative Nausea and Vomiting (PONV): Document the occurrence of nausea and vomiting postoperatively.Time to Return to Normal Activities: Time to return to normal daily activities, including mobility and routine tasks, measured postoperatively.Blood Levels of Inflammatory Markers: C-Reactive Protein (CRP): Measured preoperatively and at 24 and 72 hours postoperatively.

Interleukin-6 (IL-6): Measured preoperatively and at 24 and 72 hours postoperatively. Blood samples will be collected and analyzed using ELISA or another validated assay

Inclusion criteria

• Adults aged 18-65 years.
• Scheduled for elective laparoscopic cholecystectomy
• Informed consent obtained.

Exclusion criteria

1 - Allergies to anesthetics or saline. 2-Previous shoulder surgery. 3-Significant comorbidities (e.g., chronic pain syndromes, autoimmune diseases). 4-Pregnancy or lactation.

5-Current use of anti-inflammatory medications or steroids