Comparison Between Ultrasound-guided Ilioinguinal, Iliohypogastric Nerve Blocks, TAP Block and Quadratus Lumborum Block in Patients Scheduled for Lower Segment Ceserian Sections. A Randomized Controlled Trial

One hundred and fifty patients belonging to the American Society of Anesthesiologists physical status 1 and 2, aged between 18 and 45 years and will be scheduled for emergency or elective lower segment cesarean section (LSCS) under general anesthesia will be selected between (December 2022 to March 2023, written informed consent will be obtained from all participants.

Inclusion criteria: ASA 1& 2, Age between 18 and 45 years , scheduled for emergency or elective CS under spinal anesthesia; While exclusion criteria:pregnant women who will refuse to participate, known allergy to local anesthetic, infection at the block site.

Patients who will not willing to give consent, known allergy to local anesthetic or infection at the block site will be excluded from the study.

All patients will receive standard premedication according to institute protocol with ranitidine and metoclopramide intravenously immediately before shifting the patient into the operating room for emergency LSCS or 2 h before by oral route in case of elective LSCS. Inside the operating room under all aseptic precautions, spinal anesthesia will be administered using 1.8 ml of 0.5% of heavy bupivacaine without any adjuvant in L3-L4 space using Quincke's needle by the attending anesthesiologist. The case will be managed by the same person without any narcotics intraoperatively. At the end of the procedure just before the skin closure, 1 g of injection paracetamol will be administered intravenously over a period of 20 min as a part of multimodal analgesia. At the end of the surgery, patients will be randomized into ILIH (50 patients) , TAP block group (35 patients) or quadratus lumborum group (50 patients) by choosing a closed envelope, which will contain a standard data collection sheet and an allocation card. All the blocks were performed by the principle investigator under aseptic precautions and ultrasound guidance using high frequency linear probe resonating at 12 MHz in the multi-beam mode. In TAP block group, the probe will be placed perpendicular to the mid-axillary line between the iliac crest and the subcostal margin and the three abdominal muscle layers will be identified, and the transverses abdominis plane will be located between the internal oblique and the transverse abdominis muscle. The TAP will be approached through in-plane technique using a 23-gauge Quincke spinal needle attached to a 20 ml syringe of 0.25% bupivacaine will be injected and the drug spread in the plane will be observed. The same procedure will be repeated on the other side of the abdomen.

In ILIH group, the probe will be placed medial to the lateral one-third of the line joining the umbilicus and the anterior superior iliac spine (ASIS), with part of the probe sitting on the ASIS. The ASIS, iliacus muscle, internal oblique, transverses abdominis, and the ILIH nerves between them will be identified. After appreciating the sonoanatomy, the ILIH nerve will be approached with the 23-gauge Quincke spinal needle through in-plane technique and 10 ml of 0.25% bupivacaine will be injected all around and the drug spread will be appreciated. The same procedure will be repeated on the other side.