Role of dexmedetomidine as an adjuvant to bupivacaine in external oblique intercostal plane block for post thoracotomy pain: a randomized controlled trial

BACKGROUND: The duration of peripheral nerve blocks is extended with dexmedetomidine, which has a beneficial impact in reducing the amount of opioid consumption and pain score during and after surgery. The external oblique intercostal plane block (EOIPB) is a new method that specifically targets the sensory nerves responsible for supplying the chest wall, providing pain relief for surgical techniques. This trial's goal was to evaluate the effectiveness of dexmedetomidine as an adjuvant in EOIPB for the management of post-thoracotomy pain (PTP). METHODS: In this controlled, randomized, double-blind trial, 40 adult patients of both sexes had open thoracotomies. The patients were divided into two groups: Group D was given 29 mL of 0.25% bupivacaine and 0.5 μg/kg of dexmedetomidine diluted in one mL of saline 0.9%, and Group C (Control Group) received 29 mL of bupivacaine 0.25% plus one mL of saline 0.9%. Total morphine usage over the first 48 hours after surgery was the primary outcome. The secondary outcomes were intraoperative hemodynamics, intraoperative fentanyl consumption, total morphine intake in the first 24 hours, time to the first rescue analgesia, pain score, and the level of patient satisfaction and side effects. RESULTS: Total amount of morphine taken in the first 24 and 48 hours postoperative was markedly reduced in Group D, in contrast to Group C (P<0.05). The first request for rescue analgesia was considerably delayed in Group D, in contrast to Group C (P<0.001). Numerical Rating Scale measurements were notably reduced at 4h, 8h, 12h, and 18h in Group D in contrast to Group C (P<0.05). Patient satisfaction was substantially greater in Group D than in Group C (P=0.041). CONCLUSIONS: The addition of dexmedetomidine to bupivacaine as an adjuvant in the EOIPB resulted in effective postoperative analgesia by lowering pain scores and the need for postoperative opioids and delaying the time of the first rescue analgesia.