92. Complications of cervical epidural steroid injections

Abstract

<h3>BACKGROUND CONTEXT</h3> Cervical epidural steroid injections (CESIs) are common in the diagnosis and treatment of cervical pathology. Rare and catastrophic complications have been reported, although prior studies have been limited by the paucity of cases. This study investigated the incidence of, and predictors for, severe procedural and medical complications associated with CESIs using deidentified national administrative claims data. <h3>METHODS</h3> The IBM® MarketScan® Commercial Claims and Encounters and Medicare Supplemental databases (2007-2015) were retrospectively analyzed. Each CESI was recorded for patients age 18 or older with active enrollment for at least one year before and 90 days after injection. Patients with neoplasm, fracture, infection, inflammatory spondyloarthropathy or cervical surgery within one year preceding the injection were excluded. If a second CESI occurred before a complication, that complication was attributed to the second injection to avoid double-counting. Multivariable repeated measures logistic regression models evaluated relationships between demographics, comorbidities, and diagnoses, and overall complication rates at 2, 7, 30 and 90 days. The patient was treated as the repeated factor to adjust for patients having multiple CESIs. Each time point was modeled separately, and level of significance was Bonferroni-adjusted for 4 time points (α=0.05/4=0.0125). <h3>RESULTS</h3> A total of 448,209 CESIs were included (age 52.2 ± 11.3 years, 57.1% female). At least one additional CESI had been performed within the prior year in 48.1% of patients. Complications totaled 1.7% 7 days following CESI with fewer procedural (0.6%) than medical complications (1.2%). Complications increased to 8.1% by 90 days, driven by medical complications (7.5%). Only 0.3% of patients required admission within 7 days. Direct root/cord injury (0.3%), stroke (0.2%), and dysrhythmia (0.5%) were predominant within 7 days of CESI. Other procedural complications were identified but remained rare. Overall complication risk within 7 days of CESI was most strongly associated with CHF [OR (95% CI): 3.08 (2.72, 3.49); p<0.001], increasing age [OR: 3.05 (2.34, 3.99) for the oldest vs youngest age groups; p<0.001], existing neurologic deficits [OR: 1.82 (1.65, 2.00); p<0.001], and transforaminal approach [OR: 1.22 (1.12, 1.34)]. Multiple procedure-related diagnoses, cardiac comorbidities, diabetes, obesity, tobacco use and southern US residence were also associated with increased complications. Results from 90-day models were similar. Neurologic complications, including both direct injuries and strokes, were most strongly predicted by existing neurologic deficits (OR: 1.93 [1.73, 2.15]; p<0.001), and were also related to transforaminal approach, increasing age, multiple procedure-related diagnoses and medical comorbidities. Most direct injuries were reported within 7 days, while stroke rates increased at each time point. Myelopathy was not associated with neurologic injury. Overall complication rates did not change significantly by year from 2007-2015, although neurologic injury rates decreased slightly (OR: 0.97 [0.96, 0.99]; p<0.001). <h3>CONCLUSIONS</h3> While complications following CESIs are rare, catastrophic complications were identified. Neurologic injuries were the most frequent procedural complications and were most strongly associated with prior neurologic deficits. Multiple factors associated with procedural and medical complications were identified. Overall complication rates did not change by year, emphasizing the need to improve safety in at-risk patients and minimize catastrophic complications. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.