Paravertebral anesthetic nerve block for pain control after peroral endoscopic myotomy.

BACKGROUND: Excess post-operative opioid medication use can delay recovery and is associated with long-term misuse, addiction, and overdose. We aimed to explore the effect of pre-procedural thoracic paravertebral nerve block (PNB) on pain-related outcomes after POEM. METHODS: In this retrospective cohort study, consecutive patients who did and did not receive a PNB prior to POEM were compared. The outcomes were peak and cumulative pain scores, total opioid use during hospitalization, and length of stay. After adjusting for confounders, the associations between nerve block and the outcomes of interest were explored. RESULTS: Forty-nine consecutive patients were enrolled; 25 patients received a block whereas the subsequent 24 did not. There were no differences in baseline characteristics between the study groups. In unadjusted analyses, there was no significant difference between patients who did and did not undergo PNB in peak pain score (7.8 vs. 8.7, p=0.14), cumulative pain score in the first 12 hours (area under curve 66.5 vs. 75.8, p=0.22), median total opioid use (38.9 mg morphine equivalent dosing vs. 42, p=1.00), and median length of hospitalization (26.5 hours vs. 24, p=0.35). In multivariable regression models, PNB was not associated with a reduction in pain scores, opioid use, or hospitalization. There were no adverse events related to the block. CONCLUSIONS: In this exploratory, observational study, paravertebral nerve block immediately before POEM did not result in a statistically significant reduction in pain-related outcomes or hospitalization. Additional observational studies may elucidate whether higher anesthetic doses or longer acting formulations would be of value.