Acute low back pain of extra-axial non-traumatic origin: clinical and radiological overview from a high-load tertiary emergency department
Author Block: P. A. Bonaffini1, E. Piccin1, C. Preti2, R. Cosentini2, C. Valle1, P. Marra1, S. Sironi1; 1Monza/IT, 2Bergamo/IT
Purpose: To report prevalence and etiologies of acute extra-axial non-traumatic low back pain (ALBP, <3 months onset), in patients admitted in a high-load tertiary emergency department (ED) over 2-year (2018-2020). To review radiological features and imaging contribution in ALBP, using discharge or ward admittance diagnosis as reference.
Methods or Background: Patients admitted to ED were retrospectively divided according to back pain onset (chronic/acute) and origin (traumatic/non-traumatic, axial/extra-axial): chronic pain, trauma-related and axial causes were excluded. Clinical evaluation during admittance was checked; then, abdominal, genitourinary, gynecological, infectious, rheumatological and cardio-pulmonary etiologies were categorized by final diagnosis at discharge or ward admittance. Then imaging results (plain radiography, US, CT) for each category were reviewed and reported.
Results or Findings: Among 46.449 patients, 2024 (23%) were admitted for lumbar pain: in 78.6% chronic-traumatic-musculoskeletal, in 21,4% extra-axial non-traumatic (ALBP). In ALBP final diagnosis was: 212 patients(49,5%) with urinary disease (kidney stones, pyelonephritis, cystitis), 95(22,2%) abdominal (constipation, biliary cholic), 67(15,6%) gynecologic (including pregnancy), 24(5,6%) infectious (influenza, fever), 21(4,9%) cardio-pulmonary (pneumonia, pericarditis), 7(1,6%) rheumatologic (polyarthritis) and 1(0,2%) vascular (dissection). US was the most employed technique (26,9%; 31,6% patients with urinary, 24,2% abdominal, 14,9% gynecological, 28,9% infectious diseases and for aortic dissection). Plain radiography was used to exclude perforation/occlusion (13,4%). CT used was in 9 patients (2,1%) as completion (inconclusive US/plain radiography), including aortic dissection. In 264 patients (61,7%) imaging was not performed: diagnosis was gained through clinical/laboratory data.
Conclusion: ALBP is a relevant cause of access to ED. In 20% of cases origin is related to abdominal causes, being urinary diseases the most common. With inconclusive clinical-laboratory evaluation (40%) imaging can aid in confirming pain origin. US is essential for kidney-abdominal evaluation, CT could be reserved to selected cases, sparing unnecessary radiation exposure.
Limitations: Retrospective
Funding for this study: Not applicable
Has your study been approved by an ethics committee? Not applicable
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