Efficacy of External Oblique Intercostal Plane Block versus Transversus Abdominis Plane Block for Postoperative Analgesia in Laparoscopic Upper Abdominal Surgeries: A Randomised Clinical Study

Abstract

Introduction: Fascial plane blocks play a major role in aiding Enhanced Recovery After Surgery (ERAS) following upper abdominal wall surgeries. The External Oblique Intercostal (EOIC) plane block is a novel technique that targets the anterior and lateral cutaneous branches of the thoracoabdominal nerves. Aim: To compare the efficacy of the EOIC plane block with the Transversus Abdominis Plane (TAP) block. Materials and Methods: This double-blinded randomised clinical study was conducted at Narayana Medical College, Nellore, Andhra Pradesh, India, between June 3, 2023, and February 25, 2024, on 100 patients after obtaining ethical committee approval. These patients underwent upper abdominal surgeries, with 50 patients receiving bilateral EOIC block (Group E) and 50 patients receiving bilateral TAP block (Group T) using 0.25% Levobupivacaine and 8 mg Dexamethasone in a total volume of 30 mL on each side. The demographic details studied included age, sex, American Society of Anaesthesiologists (ASA) physical status, weight and key parameters such as dermatomal distribution, extent of analgesia, Numerical Rating Scale (NRS), time for first rescue analgesia, number of rescue analgesic doses and the Bruggemann comfort scale. Data were analysed using the Chi-square test for categorical data and the unpaired Student’s t-test for numerical data. Results: The demographic data did not differ significantly between the groups. Both groups had comparable average ages (Group E: 66.8 years; Group T: 67.1 years) and similar gender distributions. The distribution of patients across ASA classifications I, II and III, as well as heights and body weights, was also statistically similar and lacked significant differences. Patients who received the EOIC block exhibited greater dermatomal blockade from T4 to T10 in the midclavicular, anterior axillary and midaxillary lines compared to those who received the TAP block. The NRS scores at 6, 12 and 24 hours after surgery in Group E were lower than in Group T. The time taken for the first rescue analgesia was 12±4.2 hours in Group E compared to 4.4±3.02 hours in Group T, which was statistically significant. The number of rescue analgesic doses was 1.06±0.84 in Group E, compared to 3.52±1.3 in Group T, which was also significant (p<0.05). The Bruggemann comfort scale was superior in Group E compared to Group T, with statistical significance. Conclusion: The EOIC block is a superior and effective alternative to the TAP block for postoperative analgesia in laparoscopic upper abdominal wall surgeries. The extent of analgesia and dermatomal distribution of the EOIC block was greater than that of the TAP block, making the EOIC block more efficacious.

Keywords

• bruggemann comfort scale
• intercostal nerves
• laparoscopy