A randomized controlled trial comparing isobaric versus hypobaric plus isobaric drug in segmental thoracic spinal for reducing shoulder pain during laparoscopic cholecystectomy

Preoperative Preparation

Written informed consent will be obtained from all participants. Preoperative evaluation will include a complete clinical examination, CBC, renal function tests, liver function tests, ECG, and, where indicated, chest X-ray and echocardiography. Anxiety levels will be assessed using a validated scale to ensure comparability among groups.

Anesthesia Procedure

Anesthesia will be provided by a senior consultant proficient in segmental thoracic spinal anesthesia. Patients will be positioned sitting for the spinal block, and standard monitoring (ECG, NIBP, SpO2) will be initiated. Under aseptic precautions, subarachnoid block will be performed using a 27G Quincke Babcock needle. For thoracic spinal anesthesia, the T9-T10 space will be identified using anatomical landmarks (C7 spine, T7 scapular level, L1 corresponding to the 12th rib).

Following the block, patients will be immediately placed in the supine position, and oxygen will be administered at 4-6 L/min via a mask. Vital signs will be recorded every minute for the first 15 minutes, then every 5 minutes until the completion of surgery. Sensory levels will be assessed with a pinprick test, aiming for coverage from of required dermatome. Motor blockade will be assessed using the Bromage scale. Hypotension (SBP <90 mmHg) will be treated with intravenous mephentermine (6 mg), and bradycardia (HR <50/min) with atropine (0.6 mg). Sedation will be achieved with intravenous midazolam (1 mg) and fentanyl (1-1.5 mcg/kg). Postoperative shoulder pain will be treated with tramadol (50 mg) if needed, and intraoperative nausea and vomiting with ondansetron (4 mg).

Statistical Analysis

Data will be collected using standardized forms. Data will be analyzed using SPSS version 25. Continuous variables (e.g., pain scores, hemodynamic parameters) will be expressed as means ± standard deviation and analyzed using paired t-test or Mann Whitny U-test depending on the distribution of data. Categorical variables (e.g., incidence of shoulder pain) will be compared using Chi-square or Fisher’s exact test. A p-value of < 0.05 will be considered statistically significant. Logistic regression will be performed to control for potential confounding variables.