Effect of Bilateral Oblique Subcostal TAP Block on Multimodal Analgesia for Upper Abdominal Incisions: Two Case Reports

Severe somatic pain often follows upper abdominal incisions and may not be adequately controlled by systemic opioids alone. The oblique subcostal transversus abdominis plane (OSTAP) block targets T7–T10 dermatomes to enhance multimodal analgesia. Two patients undergoing major upper abdominal procedures received bilateral ultrasound-guided OSTAP blocks before emergence from anesthesia. Case 1 was a 73-year-old man (78 kg) with type 2 diabetes mellitus who underwent open gastrectomy for gastric adenocarcinoma. Case 2 was a 55year-old woman (86 kg) who underwent cytoreductive debulking for ovarian carcinoma. Both received identical anesthetic protocols (premedication: midazolam 2 mg IV; induction: propofol 2 mg/kg, fentanyl 2 µg/kg, rocuronium 0.6 mg/kg), intraoperative IV paracetamol 1 g, tramadol 2 mg/kg, and ondansetron 0.1 mg/kg, plus invasive arterial pressure and core temperature monitoring during ≈ 8 h of surgery. Before emergence, each patient received 20 mL of 0.25 % bupivacaine per side via OSTAP block. On PACU admission, their VAS scores were 2/10 (Case 1) and 3/10 (Case 2). The first request for additional analgesia occurred at 14 h in Case 1 and at 12 h in Case 2. No complications were observed. Ultrasound-guided bilateral OSTAP block is a safe and effective adjunct to multimodal analgesia in upper abdominal surgery, providing prolonged somatic pain relief and significantly delaying early opioid requirements across different patient profiles.