Back Cracking Red Flags

 

Written by; Victor Bernal, DO; Edited by: Timothy Khowong, MD

 

Case:

72 yo M with prostate cancer presents for low back pain x 5 days. Endorses b/l weakness and difficulty ambulating. Denies fever, urinary complaints, incontinence. 

The majority of emergency department presentations for low back pain are usually secondary to benign processes.. Despite the majority of benign causes, some patients will present with more serious pathologies that can lead to significant neurological disability or non-spinal causes of acute back pain (i.e. abdominal aorta dissection) that can have a high mortality. Patients with low back pain with red flags suggesting serious pathology should receive emergent imaging in the emergency department. X-Rays are neither sensitive nor specific for the workup of lower back pain. Additionally, the use of opiates is discouraged, and alternative modalities of pain treatment should be pursued first. Patients with red flags along with their back pain should be considered for imaging (MRI) in the ED.

Red Flags in Patient History:

  • New onset of back pain at extremes of age (< 20 years or > 50 years)

  • History of cancer

  • Constant, non-mechanical back pain, or pain worse when lying down

  • Presence of neurologic symptoms (weakness and numbness)

  • Bilateral symptoms

  • Immunosuppression (i.e. HIV/AIDS, corticosteroids, immunomodulating drugs)

  • IVDU

  • Change in bowel/bladder function (increased or decreased function) or erectile dysfunction

  • Fever or night sweats

  • Anticoagulant use

Red Flags in Physical Exam:

  • Focal neurologic signs and symptoms are specific but not sensitive (Edlow 2015)

  • Concerning physical exam findings

  • Motor – weakness in legs or arms

  • Sensory – saddle anesthesia

  • Reflexes – diminished or abnormal reflexes 

    • including positive Babinski sign

  • Sphincter dysfunction – decreased rectal tone or post-void residual >100 ml (Edlow 2015)

  • Midline tenderness to palpation or percussion

Emergent Differential Causes of Low Back Pain:

  • Abdominal Pathology

    • Vascular

      • Aortic dissection

      • Abdominal aortic aneurysm (AAA)

      • Renal artery dissection or thrombosis

    • Pyelonephritis

    • Retroperitoneal hemorrhage

    • GI Causes (i.e. pancreatitis, peptic ulcer, cholecystitis)

  • Oncologic

    • Epidural metastatic disease

    • Intradural metastatic disease

    • Intramedullary tumor

  • Infectious

    • Spinal epidural abscess

    • Vertebral osteomyelitis

    • Infectious discitis

  • Spinal epidural hematoma

  • Cauda equina syndrome (from disc herniation)

 
 
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