Upper abdominal surgeries often involve various incisions, such as subcostal, inverted L-shaped, vertical, transverse, and oblique, which can lead to significant postoperative pain1. Effective pain management is crucial for ensuring early mobilization and a smooth recovery. Regional anaesthesia techniques are integral to perioperative care, forming a key component of multimodal pain management strategies that help reduce reliance on opioids and their side effects.

Traditionally, the thoracic epidural block has been the gold standard for pain relief in abdominal surgeries due to its superior analgesic properties. However, it comes with potential complications, including sympathetic blockade, hypotension, and rare but serious risks like epidural hematoma or spinal cord compression. These concerns are heightened in patients with coagulopathy or those undergoing extensive procedures.

Recently, the Erector Spinae Plane Block (ESPB) has gained prominence as a promising alternative for managing postoperative pain in abdominal surgeries. It offers effective pain relief while avoiding many complications associated with thoracic epidural analgesia. Similarly, superficial interfascial blocks are becoming increasingly popular in clinical practice due to their simplicity, ease of administration, and safety, particularly in patients where repositioning or coagulopathy is a concern.

Among these newer techniques, the External Oblique Intercostal (EOIPB) Block is attracting attention. This block targets the anterior and lateral cutaneous branches of the intercostal nerves and has demonstrated positive outcomes in various upper abdominal surgeries, including hepatic resections, open cholecystectomies, and pancreatic procedures.

This study aims to conduct a randomized clinical trial comparing the analgesic efficacy of ultrasound-guided External Oblique Intercostal Plane Block and Erector Spinae Plane Block. These techniques will be evaluated as part of a multimodal analgesia plan for patients undergoing upper abdominal surgeries with unilateral subcostal incisions. The trial will assess these blocks in terms of pain control, reduction in opioid usage, patient satisfaction, and overall safety.