Reducing postoperative opioid consumption by adding an ultrasound-guided rectus sheath block to multimodal analgesia for abdominal cancer surgery with midline incision.

BACKGROUND: Many multimodal analgesia techniques have been tried to provide adequate analgesia for midline incisions extending above and below the umbilicus aiming at limiting the perioperative use of morphine thus limiting side effects. Ultrasound (US) guidance made the anesthesiologist reconsider old techniques for wider clinical use. The rectus sheath block (RSB) is a useful technique under-utilized in the adult population.

OBJECTIVES: Our study examined the efficacy of a preemptive single-injection rectus sheath block in providing better early postoperative pain scores compared to general anesthesia alone.

PATIENTS AND METHODS: Sixty patients were recruited in this randomized controlled trial. These patients were divided into two groups: RSB group had an RSB after induction of anesthesia and before surgical incision, and GA (general anesthesia) group had general anesthesia alone. Both groups were compared for verbal analogue scale (VAS) score, opioid consumption and hemodynamic variables in the post-anesthesia care unit (PACU). Analgesic requirements in surgical wards were recorded in postoperative days (POD) 0, 1 and 2.

RESULTS: The median VAS score was significantly lower in RSB group compared with GA group in all 5 time points in the PACU (P ˂ 0.05). Also PACU morphine consumption was lower in RSB group than GA group patients (95% confidence interval [CI] of the difference in means between groups, -4.59 to -2.23 mg). Morphine consumption was also less in the first 2 postoperative days (POD0 and POD1).

CONCLUSIONS: Ultrasound-guided rectus sheath block is an easy technique to learn. This technique, when it is used with general anesthesia, will be more effective in reducing pain scores and opioid consumption compared with general anesthesia alone.