Purpose: Microwave ablation (MWA) of liver tumors is associated with post-ablation pain in up to 30% of patients. (1,2) In the surgery and anesthesia literature, protocols of enhanced recovery after surgery (ERAS) have been studied and applied clinically. (3,4) 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.
Materials and Methods: 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-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 manevure for hypoxia (SpO2< 90%).
Results: 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 7.64mg, p=0.80), or post procedure tramadol (6.12 mg vs 2.83 mg , p=0.27). There were no PPRE events recorded.
Conclusion: 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.
References: 1. Andreano A, Galimberti S, Franza E, Knavel EM, Sironi S, Lee FT, et al. Percutaneous microwave ablation of hepatic tumors: Prospective evaluation of postablation syndrome and postprocedural pain. J Vasc Interv Radiol. 2014;25(1):97–105.
2. Simon CJ, Dupuy DE, Mayo-Smith WW. Microwave ablation: principles and applications. Radiographics. 2005;25(Suppl 1):S69-83.
3. Ljungqvist O. ERAS - Enhanced Recovery after Surgery: Moving Evidence-Based Perioperative Care to Practice. J Parenter Enter Nutr. 2014;38(5):559–66
4. Semenkovich TR, Hudson JL, Subramanian M, Kozower BD. Enhanced Recovery After Surgery (ERAS) in Thoracic Surgery. Semin Thorac Cardiovasc Surg. 2018;30(3):342–9.