Comparison of thoracic epidural catheter and continuous peripheral infusion for management of traumatic rib fracture pain.

BACKGROUND Thoracic epidural catheters (TECs) are useful adjuncts to multimodal pain regimens in traumatic rib fractures. However, TEC placement is limited by contraindications, patient risk profile, and provider availability. Continuous peripheral infusion of ketamine and/or lidocaine is an alternative that has a modest risk profile and few contraindications. We hypothesized that patients with multiple traumatic rib fractures receiving TECs would have better pain control, in terms of daily morphine milligram equivalents (MMEs) and mean pain scores (MPSs) when compared with continuous peripheral infusions of ketamine and/or lidocaine. METHODS We retrospectively analyzed traumatic rib fracture admissions to a level 1 trauma center between January 2018 and December 2020. We evaluated two treatment groups: TEC only and continuous infusion only (drip only). A linear mixed-effects model evaluated the association of MME with treatment group. An interaction term of treatment group by time (days 1-7) was included to allow estimating potential time-dependent treatment effect on MME. A zero-inflated Poisson mixed-effects model evaluated the association of treatment with MPS. Both models adjusted for confounders. RESULTS A total of 1,647 patients were included. After multivariable analysis, a significant, time-varying dose-response relationship between treatment group and MME was found, indicating an opioid-sparing effect favoring the TEC-only group. The opioid-sparing benefit for TEC-only therapy was most prominent at day 3 (27.4 vs 36.5 MME) and day 4 (27.3 vs 36.2 MME) (p < 0.01). The drip-only group had 1.21 times greater MPS than patients with TEC only (p < 0.001). CONCLUSION Drip-only analgesia is associated with higher daily MME use and MPS, compared with TEC only. The maximal benefit of TEC therapy appears to be on days 3 and 4. Prospective, randomized comparison between groups is necessary to evaluate the magnitude of the treatment effect. LEVEL OF EVIDENCE Therapeutic/Care Management; Level III.