Most back pain is mechanical and gets better on its own, but a small group of patients have a serious cause such as cauda equina syndrome, spinal infection, cancer, fracture or a leaking aortic aneurysm. Red flags in the history and exam tell you who needs urgent imaging and specialist care.
Key symptoms
- New back pain with fever, weight loss or a history of cancer
- Numbness in the saddle area, new trouble passing urine or loss of bowel control
- Leg weakness that is getting worse
- Pain that is constant, worse at night or not eased by rest
- Sudden severe back or flank pain in an older patient, sometimes with fainting
What you find on exam
- Vital signs: fever, fast heart rate, low blood pressure
- Strength, sensation and reflexes in both legs
- Saddle sensation and anal tone; bladder scan for retained urine
- Spine tenderness over one level, and a pulsatile mass in the abdomen
- Leg pulses and skin color for signs of poor blood flow
Tests
- Emergency MRI of the spine for suspected cord or cauda equina compression
- Blood count, ESR and CRP, blood cultures if infection is possible
- Bedside ultrasound or CT angiography if an aortic aneurysm is suspected
- Post-void residual urine volume
Treatment basics
- Scene and transport: position of comfort, spinal motion restriction after trauma
- Pain control and IV access; fluids with care if the aorta may be leaking
- Urgent spine surgery consult for cauda equina or cord compression
- IV antibiotics for spinal infection after cultures; dexamethasone for cancer compression
- Vascular surgery right away for a ruptured or symptomatic aneurysm
Red flags
- Saddle numbness with urinary retention or incontinence
- Progressive weakness in one or both legs
- Back pain with low blood pressure, a pulsatile mass or fever in a drug injector
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; NASEMSO National Model EMS Clinical Guidelines. Written by Making Synapses. Making Synapses is not affiliated with these organizations.