ABSTRACT
Emergency departments across the nation are confronted multiple times a day with patients who present with complaints of acute low back pain. The role of the practitioner in the emergency department is to carefully evaluate the low back pain symptom as a potentially serious illness. The primary focus of this article is to discuss the historical and physical "red flags" that warrant a more detailed evaluation of this common chief complaint. Nonspecific low back pain is a diagnosis of exclusion. History is the key to differentiating mechanical acute low back pain from more serious etiologies. Age, duration of pain, history of trauma, location and radiation of pain, systemic complaints, history of cancer, neurologic deficits, psychological and social risks, and functional pain are important considerations during history taking. The physical examination of the patient with acute low back pain is based on the history and guides the practitioner to determine the extent of examination necessary to distinguish serious from more simple nonspecific low back pain. Abnormal vital signs are of particular concern and are "red flags." The focused physical examination of the back includes inspection of the back, range of motion, and a thorough neurologic examination. An abdominal examination should be conducted to exclude intra-abdominal pathology such as aneurysm or masses. Rectal examinations are critical in anyone with complaints of saddle anesthesia or who may have cauda equina syndrome. Nonorganic are also causes for low back pain. Diagnostic studies include laboratories for infection, radiograph studies when the patient meets criteria, computerized axial tomography, and magnetic resonance imaging along with ultrasound aid in the differential diagnosis of patients with low back pain. Admission criteria of patients with nonspecific low back pain without evidence of neurologic findings is the inability to perform activities of daily living at home. The goal for patients with acute low back pain is the restoration of normal daily activities with medications, activity, patient education, and, at times, adjuvant therapy. Overall, the prognosis is good for patients with mechanical low back pain.