The association between patient- and procedure-related factors and patient-reported intraprocedural pain during fluoroscopically guided lumbar epidural injections: A real-world cohort study.

Background: Fluoroscopically guided lumbar epidural steroid injections (ESIs) are commonly performed to treat lumbar radicular pain. Intraprocedural pain is an important patient centered aspect of the procedural experience and may influence satisfaction, anxiety, and willingness to undergo repeat interventions. Although prior studies have suggested that interlaminar approaches may be less painful than transforaminal injections, the patient and procedure related factors associated with intraprocedural pain in routine clinical practice remain incompletely characterized. Objective: 1. To evaluate the association between patient- and procedure-related factors and intraprocedural pain during lumbar epidural steroid injections. 2. To compare intraprocedural pain between lumbar transforaminal epidural steroid injections (LTFESI), lumbar interlaminar epidural steroid injections (LIESI) and caudal epidural steroid injections. Methods: This single-center observational cohort study analyzed consecutive adult patients who underwent fluoroscopically guided LTFESI, LIESI or caudal injections between February 2022 and June 2022. Pain scores were collected immediately before and after the procedure, with intraprocedural pain assessed using immediate recall. Scores were obtained by non-physician staff while the performing physician was not present. Demographic variables including age, sex, and body mass index were obtained through electronic medical record review. Multivariable linear regression analyses were performed to evaluate associations between patient- and procedure-related factors and intraprocedural pain scores. Results: A total of 582 injections were performed. The mean intraprocedural pain score was 4.57 ± 2.79 on a 0 to 10 numeric rating scale. Increasing age was significantly associated with lower intraprocedural pain scores (β = -0.029; 95% CI -0.043 to -0.014; p < 0.001), while male sex was associated with lower reported pain compared with female sex (β = -0.59; 95% CI -1.05 to -0.12; p = 0.013). Higher pre-procedure pain (β = 0.24; 95% CI 0.14 to 0.34; p < 0.001) and greater injectate volume (β = 0.45; 95% CI 0.12 to 0.77; p = 0.007) were independently associated with higher intraprocedural pain after adjustment for injection approach and other covariates. In contrast, injection approach (LTFESI vs. LIESI vs. caudal ESI) itself was not associated with intraprocedural pain. Conclusion: In this real-world cohort, younger age, female sex, higher pre-procedure pain and higher injectate volume were associated with increased intraprocedural pain during fluoroscopically-guided lumbar ESIs. There were no differences in intraprocedural pain scores between LTFESI, LIESI, and caudal injections. These findings highlight the importance of considering patient-specific demographic factors when counseling patients and optimizing strategies to improve procedural comfort.