Abstract No. 20 Assessment of pre-emptive multimodal analgesia to reduce post-procedural opioid requirements in patients undergoing liver microwave ablation

Abstract

Microwave ablation (MWA) of liver tumors is associated with post-ablation pain in up to 30% of patients. In the surgery and anesthesia literature, protocols of enhanced recovery after surgery (ERAS) have been studied and applied clinically. Central to the ERAS protocols is multimodal pre-emptive analgesia, with the goal of decreasing opioid consumption and post-operative pain, while increasing patient safety and satisfaction. This study evaluated the effect and safety of an evidence-based pre-emptive multimodal analgesic regimen in reducing total opioid requirements in patients undergoing liver MWA. This is a single-center retrospective review of 207 patients (M:F = 142:65, mean age = 66 ± 9.9 years) who underwent 244 image-guided percutaneous liver MWA consecutively between January 2017 and December 2019. Cases with pre-procedural multimodal analgesia (PPMA) (191 procedures) were compared to cases without PPMA (53 procedures). PPMA included premedication with ≥1 analgesic (acetaminophen, celecoxib, gabapentin, tramadol, or topical lidocaine patch). The primary outcomes measured were total opioid utilization (intra-procedural and post-procedural) reported in morphine milligram equivalents (MME), patient reported pain via a visual analog scale (VAS), and post-procedure respiratory events (PPRE) defined as any airway rescue maneuver for hypoxia (SpO2< 90%). Within the PPMA group, postoperative MME (3.97mg vs 8.70mg, P = 0.02) and visual analog pain score at > 120 min post-procedurally (2.05 vs 3.12, P = 0.03) was significantly reduced. There was no difference in hospital admissions (23% vs 21%, P = 0.74), post procedure ketorolac (8.11mg vs 7.64 mg, P = 0.80), or post procedure tramadol (6.12 mg vs 2.83 mg, P = 0.27). There were no PPRE events recorded. In patients undergoing liver MWA for hepatic neoplasms, administration of PPMA was safe and resulted in less total opioid utilization and lower patient-reported pain. Utilization of PPMA for MWA of liver tumors can significantly reduce patient pain post-procedurally and decrease the amount of opioid medications prescribed.