Comparison of intravenous lidocaine versus epidural anesthesia for traumatic rib fracture pain: a retrospective cohort study.

BACKGROUND: Effective analgesia is essential in managing traumatic rib fractures. Intravenous lidocaine (IVL) is effective in treating perioperative pain, acute pain in the emergency department, cancer pain in hospice, and outpatient chronic neuropathic pain. Our study examined the associations between IVL versus epidural analgesia (EA) and pain for the treatment of acute rib fracture in the inpatient setting.
METHODS: We performed a retrospective study involving adults admitted to an academic level I trauma center from June 1, 2011 to June 1, 2016 with consults to the pain service for acute rib fracture pain. Eighty-nine patients were included in the final analysis (54 IVL and 35 EA patients). Both groups had usual access to opioid medications. The primary outcome was absolute change in numeric pain scores during 0-24 and 24-48 hours after initiating IVL or EA, compared with baseline. Secondary outcomes include opioid consumption, incentive spirometry, supplemental oxygens, pneumonia, endotracheal intubation and length of hospital stay.
RESULTS: Numeric pain scores differed at baseline (mean 5.6 for IVL vs 4.5 for EA, p=0.01), while age, injury severity, and number of fractured ribs were similar. IVL and EA were associated with similar reductions in numeric pain scores within 0-24 and 24-48 hours (mean -2.9 for IVL vs -2.3 for EA during both periods, p=0.19 and p=0.17 respectively) . There was greater non-neuraxial opioid consumption with IVL compared with EA (98.6 vs 22.3 mg morphine equivalents (MME) at 0-24 hours, p=0.0005; 105.6 vs 18.9 MME at 24-48 hours, p<0.0001). When epidural opioids were analyzed, the EA group was exposed to higher total MME at 0-24 hours (655.2 vs 98.6 MME, p<0.0001) and 24-48 hours (586 vs 105.6 MME, p=0.0001), suggesting an opioid sparing effect of IVL.
CONCLUSION: Our results suggest that IVL is similar to EA in numeric pain score reduction, and that IVL may have an opioid sparing effect when taking neuraxial opioids into account. IVL may be an effective alternative to epidurals for the treatment of rib fracture pain. It should be considered for patients who have contraindications to epidurals or are unable to receive an epidural in a timely manner. © American Society of Regional Anesthesia & Pain Medicine 2020. No commercial re-use. See rights and permissions. Published by BMJ.