Abstract
BACKGROUND: The external oblique intercostal plane block (EOIPB) is a novel block that targets explicitly the intercostal nerves to provide pain relief, reduce opioid use, and improve postoperative recovery. This study evaluated the effectiveness of dexmedetomidine (Dex) and Ketamine as adjuvants in EOIPB for post-thoracotomy pain (PTP). METHODS: This double-blind, randomised trial involved forty adults undergoing open thoracotomy. Cases were distributed equally into two groups. The Ketamine group received bupivacaine 0.25% with Ketamine, while the Dex group received bupivacaine 0.25% with dexmedetomidine. RESULTS: Patient-required intraoperative fentanyl consumption was not different between groups. Dex provided superior postoperative analgesia to Ketamine, with significantly lower pain scores at 8 h (median 2 vs. 3, p = 0.001) and 12 h (p = 0.035). Time to first rescue analgesia was prolonged (14.65 ± 2.25 vs. 10.26 ± 1.73 h, p < 0.001), and morphine consumption was notably reduced in the Dex group at both 24 h (5.4 ± 1.57 vs. 6.95 ± 1.43 mg, p = 0.003) and 48 h (7.95 ± 1.47 vs. 9.95 ± 1.43 mg, p < 0.001). The two groups did not exhibit any substantial variations in patient satisfaction and the incidences of bradycardia, hypotension, and postoperative nausea and vomiting. CONCLUSIONS: As an adjuvant in EOIPB, Dex is superior to Ketamine. It provides a longer duration of analgesia, significantly reduces postoperative opioid consumption, and results in lower pain scores at specific time intervals, without a significant difference in adverse effects. TRIAL REGISTRATION: Registration at clinicaltrials.gov (NCT06331182) Date of registration: 2024-03-17.