What labs can assess spinal cord injury?

Laboratory Tests for Assessing Spinal Cord Injury

The most important laboratory tests for assessing spinal cord injury include erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), which should be obtained in all patients with suspected nerve pain or spinal cord injury. 1, 2

Primary Laboratory Markers

Inflammatory Markers

• Erythrocyte sedimentation rate (ESR): Essential baseline test for all patients with suspected spinal cord injury 1, 2
• C-reactive protein (CRP): Crucial inflammatory marker that correlates with pressure sore grade and severity of injury 1, 3
• White blood cell (WBC) count with differential: Important for detecting infection and inflammation 1

Blood Cultures

• Two sets of bacterial (aerobic and anaerobic) blood cultures: Recommended when infection is suspected 1, 2
• Fungal blood cultures: Should be considered in patients at risk for fungal infection 2

Secondary Laboratory Tests

Hematologic Parameters

• Hemoglobin (Hb) and Hematocrit (Htc): Often reduced in SCI patients with complications like pressure sores 3
• Red blood cell (RBC) count: May correlate with severity of injury and complications 3
• Lymphocyte count: Reduced levels correlate with pressure sore grade 3

Nutritional and Metabolic Markers

• Serum iron, transferrin, and total iron-binding capacity (TIBC): Often reduced in SCI patients with complications 3
• Ferritin: Typically elevated in SCI patients with complications 3
• Total protein and albumin: Reduced levels correlate with pressure sore grade and complications 3
• Zinc and vitamin B12 levels: May be reduced in SCI patients with complications 3

Clinical Application

When to Order Laboratory Tests

• Acute trauma: Order ESR, CRP, and WBC count with differential immediately 1
• Suspected infection: Add blood cultures to the standard panel 1, 2
• Chronic SCI with complications: Consider expanded panel including nutritional markers 3

Interpretation of Results

• Elevated ESR and CRP: Suggest inflammation or infection, correlate with severity of injury 1, 3
• Abnormal WBC count: May indicate infection, particularly with elevated neutrophils 1
• Anemia with reduced iron parameters: Common in SCI patients with complications like pressure sores 3

Important Considerations

Red Flags Requiring Immediate Attention

• Fever with elevated inflammatory markers: Suggests possible infection requiring urgent intervention 1, 2
• Recent S. aureus bloodstream infection: High risk for spinal infection 1
• History of IV drug use with abnormal inflammatory markers: Increased risk of spinal infection 1, 2

Common Pitfalls

• Relying solely on laboratory tests: Laboratory findings should always be interpreted in conjunction with clinical assessment and imaging studies 1
• Overlooking nutritional parameters: Nutritional status significantly impacts recovery and complication rates 3
• Delayed blood cultures: Should be obtained before antibiotic administration for accurate results 1

Integration with Imaging

• Laboratory tests complement imaging studies but cannot replace them
• MRI remains the gold standard for assessing soft tissue and neural element damage 1
• CT is superior for evaluating bony structures but less sensitive for nerve root compression 2

Remember that while laboratory tests provide valuable information about inflammatory status and potential infection, they must be integrated with clinical assessment and appropriate imaging for comprehensive evaluation of spinal cord injury.