This randomized, prospective, double-blind study will be conducted in Mahatma Gandhi Medical College and Research Institute between June 2024 and Dec 2025. Prospective parturients who are posted for elective and emergency LSCS with no fetal compromise under spinal anaesthesia will be the study population.

Inclusion criteria: age between 18-40years, scheduled for elective and emergency cesarean section, American society of Anesthesiologist physical status II emergency LSCS with indication of previous LSCS.

Exclusion criteria: Pregnancy induced hypertension, bleeding disorder, morbid obesity, H/O OSA, H/O allergies to local anaesthetics, H/O bronchial asthma, fetal distress.

Sample size is calculated using statistics and sample size (BIOSTATVN) android application (Author - Mr. Thai thanh true version 1). Based on study by Mohammed Ahmed Hamed et al, with recommended dose of 0.2ml/kg of 0.25% Bupivacaine the pain score will be equivalent to intrathecal morphine at 8 hours of postoperative period. A minimal sample size of 64 is required in each group for a power of 0.80, alpha level of 0.05 and a median effect size of 0.7, the required number of participants in each group is 33. To overcome the dropouts, the calculated sample size is increased  to reach 45 parturients in each group.

 Participants will be enrolled by means of consecutive sampling and they will be explained about the study and written informed consent will be obtained.

They will be randomly allocated into two equal groups (the ITM group as A or the ESPB group as B ) consecutively. The participants and data collectors will be unaware of group allocation until study completion. Preoperative investigations, including an electrocardiogram (ECG), complete blood count, renal function tests, and a coagulation profile, will be performed. All parturients will be advised nil per oral (NPO) for 8 hrs prior to the surgery. Upon arrival to the pre-operating room, intravenous (IV) access will be obtained (one 18G peripheral venous cannula). In the operating theatre the routine monitoring procedures (pulse oximetry, ECG, and non-invasive blood pressure monitoring) will be initiated. All parturients will receive 8 mg ondansetron intravenously as premedication, and 10 m/kg of Ringer’s lactate solution will be infused during the spinal procedure. With the parturient in sitting position or lateral position as per patient comfort the skin on the back was sterilized and 2 mL of 2% lidocaine will be then administered as a subcutaneous infiltration. Spinal anesthesia will be performed using a midline method into the L4-5 or L3-4 interspaces with a 25G Quincke spinal needle. After confirming free flow of the cerebrospinal fluid through the needle, 12 mg of 0.5% hyperbaric bupivacaine will be slowly introduced for those in the ESPB group; those in the ITM group received a spinal injection of 12 mg of hyperbaric 0.5% bupivacaine plus 100 mcg of preservative-free morphine. The patient will then immediately be moved to the supine position with a 15° left tilt and fitted with an oxygen mask. After confirming an adequate anesthesia level, the surgical procedure will be performed with continuous hemodynamic monitoring and recording. If the systolic blood pressure is  reduced to 20% below the baseline or less than 90 mmHg, 6 mg Mephenteramine will be administered intravenously. Moreover, if the heart rate slowed to 50 beats/min or less, 0.6 mg atropine will be administered intravenously. Upon delivery of the fetus, 10 units of oxytocin will be given by IV infusion. APGAR score of the baby will be noted. At the end of the cesarean section surgery, parturients in the ESPB group will receive ultrasound guided bilateral ESPB at the level of the ninth thoracic transverse process. Parturients turned to a lateral position, and the transducer was positioned vertically 3 cm to the side of the midline to visualize the muscles of the back, the transverse process, and the pleura among the two transverse processes. Then, after subcutaneous infiltration of 3 mL of 2% lidocaine, a 22G blunt needle will be introduced in the cranial-caudal direction toward the transverse process (T9) using the in-plane method till the needle tip crosses all the muscles. After ensuring negative aspiration, interfascial injection of 0.2ml/kg mL of 0.25% bupivacaine will be performed. The procedure will be repeated on the opposite side of the back. Sham blocks will be used for participants in the ITM group; the sham blocks involved a non-invasive ultrasound scan, and a short bevel needle was gently pressed on both sides. We will instruct the participants to report any signs of local anesthetic toxicity throughout the injection procedure (eg, change in mental status, anxiety, oral numbness, and ringing in the ears). For all participants, spinal level will be assessed and recorded before the block. At the end of the cesarean section, parturients will be transported to a postoperative anesthesia care unit (PACU), and the routine monitoring procedures will be followed. Any intraoperative or postoperative nausea or vomiting will be managed with 10 mg metoclopramide. All participants will receive 30 mg ketorolac intravenously at the time of the ESPB or sham blocks. Participants will be transferred to the obstetrics ward when they attained a modified Aldrete score ≥9. Throughout the first 24 hrs, patients will receive IV paracetamol 1 g every 8 hrs for postoperative analgesia. Postoperative mean arterial blood pressure, postoperative pulse rate, and postoperative visual analogue scale (VAS) pain score (ranging from 0 to 10, where 0 indicated no pain and 10 indicated maximum pain) will be measured at rest and with cough. All of these parameters will be assessed upon arrival in the PACU and at 4, 8, 12, 16, and 24 hrs. The total tramadol intake in 24 hrs and the time to the first analgesic request will be noted. Participant satisfaction will be assessed on a 4-point scale (1: excellent, 2: good 3: fair, 4: poor). Adverse effects included nausea and vomiting (0 = no symptoms, 1 = only nausea, 2 = nausea and vomiting), respiratory depression (respiratory rate less than 10), sedation (0 = awake and alert, 1 = quietly awake, 2 = asleep but easily arousable, 3 = deep sleep, responding to painful stimulus), and pruritus (1 = no pruritus, 2 = mild pruritus, 3 = moderate pruritus, 4 = severe pruritus). The data collector will be blinded to group distribution. The primary outcome of our study will be the severity of pain, measured using the VAS score 8 hrs after the surgery during rest. Secondary outcomes are the total tramadol intake, VAS score at other postoperative time points (upon arrival to the PACU and 4, 8, 12, and 24 hrs after surgery), the time to the first analgesic request, participant satisfaction, and any side effects or complications.

Statistical analysis will be carried out using SPSS version 20.0 (IBM SPSS, US) software with Regression Modules installed. Descriptive analyses were reported as mean and standard deviation of continuous variables