The Reliability of Red Flags in Spinal Cord Compression

Abstract

Background:Acute low back pain is a common cause for presentation to the emergency department (ED). Since benign etiologies account for 95% of cases, red flags are used to identify sinister causes that require prompt management.Objectives:We assessed the effectiveness of red flag signs used in the ED to identify spinal cord and cauda equine compression.Patients and Methods:It was a retrospective cohort study of 206 patients with acute back pain admitted from the ED. The presence or absence of the red flag symptoms was assessed against evidence of spinal cord or cauda equina compression on magnetic resonance imaging (MRI).Results:Overall, 32 (15.5%) patients had compression on MRI. Profound lower limb neurologic examination did not demonstrate a statistically significant association with this finding. The likelihood ratio (LR) for bowel and bladder dysfunction (sensitivity of 0.65 and specificity of 0.73) was 2.45. Saddle sensory disturbance (sensitivity of 0.27 and specificity of 0.87) had a LR of 2.11. When both symptoms were taken together (sensitivity of 0.27 and specificity of 0.92), they gave a LR of 3.46.Conclusions:The predictive value of the two statistically significant red flags only marginally raises the clinical suspicion of spinal cord or cauda equina compression. Effective risk stratification of patients presenting to the ED with acute back pain is crucial; however, this study did not support the use of these red flags in their current form.

Red flags presented in current low back pain guidelines: a review

“…Nonspecific low back pain is commonly defined as low back pain without any known pathology [4]. Although nonspecific low back pain accounts for about 85-90 % of back pain [5][6][7], the remaining patients may have neurologic impairments (e.g., spinal stenosis, radiculopathy) or & Arianne P. Verhagen a.verhagen@erasmusmc.nl serious underlying diseases (e.g., malignancies, fractures), of which the latter necessitates timely and accurate diagnosis [6,7]. Serious pathology in patients presenting with low back pain includes malignancy, spinal fractures, cauda equina syndrome (CES), infection or aortic aneurisms.…”

Most red flags for malignancy in low back pain guidelines lack empirical support: a systematic review

“…Low back pain (LBP) remains a common condition with an estimated lifetime prevalence of about 80% [1,2]. In 1 to 5% of patients presenting with LBP to primary care, a serious underlying pathology might be the cause, which needs timely and accurate diagnosis [4]. Spinal malignancy is, however, rare with less than 1% of patients presenting to primary care with LBP found to have a malignancy (primary vertebral tumor or vertebral metastasis) [5.6] Clinicians are encouraged by guidelines for managing patients with LBP to screen for red flags that might indicate underlying serious pathology [7].…”

Managing Nontraumatic Acute Back Pain

“…The best-validated ones include history of cancer, corticosteroid use, abnormal neurologic physical findings (including new ataxia and difficulty walking), and anticoagulant use. 4,[9][10][11] It is possible that combinations of red flags and interpreting them in the context of an individual patient could improve their utility. Patients with no red flags and normal neurologic examination results are at extremely low risk for serious causes of back pain.…”