The effect of body mass index on fluoroscopic time and radiation dose during lumbar transforaminal epidural steroid injections

• Published in: The spine journal 2016-07, Vol.16 (7), p.876-883
• Main Authors: Cushman, Daniel, MD, Mattie, Ryan, MD, Curtis, Bradley, BS, Flis, Alexandra, MD, McCormick, Zachary L., MD
• Format: Article
• Language: English
• Subjects: Adult; Aged; Back pain; Body Mass Index; Epidural steroid injection; Female; Fluoroscopy; Fluoroscopy - methods; Humans; Injections, Epidural - adverse effects; Low Back Pain - drug therapy; Lumbar transforaminal; Male; Middle Aged; Orthopedics; Radiation; Retrospective Studies; Steroids - administration & dosage; Steroids - therapeutic use
• ISSN: 1529-9430; 1878-1632
• DOI: 10.1016/j.spinee.2016.03.041

Abstract Objective Transforaminal epidural steroid injections (TFESIs) are a commonly used, effective treatment for radicular pain. Accurate delivery of the injected medication helps to ensure maximum therapeutic efficacy and to decrease possible adverse events, and fluoroscopy is the preferred and most common image-guidance modality used to ensure accurate needle placement during lumbar TFESIs. However, fluoroscopic-guided lumbar TFESIs put patients at risk due to radiation exposure. The purpose of this study was to determine the relationship between body mass index (BMI) and fluoroscopy time and radiation dose during lumbar TFESIs. Design Retrospective study. Setting The study was conducted at an academic orthopedic center. All procedures were performed by physicians board-certified in PM&R and/or with subspecialty certification in sports medicine, or by a trainee under close supervision from attending physician. Participants All patients who underwent fluoroscopic-guided lumbar transforaminal epidural steroid injections between February, 2013 and March, 2015 with a documented height/weight, fluoroscopy time, and radiation dose. Interventions All patients received unilateral or bilateral lumbar transforaminal epidural steroid injections with fluoroscopic guidance. Fluoroscopy time and dose were recorded. Main outcome measures The main outcome measures were fluoroscopy time and radiation dose. A Bonferroni correction was implemented for multiple comparisons, defining statistical significance at p < .01. Results A total of 2,443 injections were performed on 1,548 patients. There were 419 normal, 572 overweight, and 557 obese patients, respectively. There were 1,426 first time injections and 1,017 repeat injections. Sixty-nine percent (1,681) were unilateral injections, and 26.4% (645) were single level injections. A trainee was involved in 1,361 (55.7%) of the injections performed. The mean fluoroscopy time for all injections was 30.0 ± 17.5 seconds, and the mean radiation dose was 2,164 ± 1,484 mGy-cm2. The mean fluoroscopy time was 27.7 ± 15.2 seconds for normal weight patients, 30.0 ± 21.0 seconds for overweight patients, and 32.2 ± 15.1 seconds for obese patients, showing a significant difference between groups (p