What nutrition labs should be ordered for wound care patients?

Nutritional Laboratory Assessment for Wound Care Patients

Serum prealbumin (transthyretin) should be the primary nutritional laboratory marker ordered for wound care patients due to its shorter half-life that better reflects acute changes in nutritional status. 1

Core Laboratory Panel for Wound Care Patients

Essential Nutritional Markers

• Prealbumin (transthyretin): Half-life of 3 days, reflects short-term nutritional changes; values <20 mg/dL indicate nutritional insufficiency and are associated with 3x higher risk of surgical site infections 1
• Albumin: Though affected by inflammation and has a longer half-life (21 days), low levels (<3.5 g/dL) correlate with wound complications 1
• Total protein: Helps assess overall protein status 1
• Transferrin: Another visceral protein marker with intermediate half-life 1

Micronutrient Assessment

• Vitamin levels:

  • Vitamin A: Promotes granulation tissue formation, enhances re-epithelialization, and can reverse steroid-induced wound healing impairment 2
  • Vitamin C: Essential for collagen synthesis 3
  • Vitamin D: Deficiency linked to poor wound healing 1
  • Vitamin B12: Particularly important for patients with small bowel disease or previous resection 1

• Minerals and trace elements:

  • Zinc: Critical for wound healing and immune function 3
  • Iron studies (ferritin, transferrin saturation): For assessment of iron deficiency 1
  • Magnesium, copper, selenium: Support enzymatic functions in tissue repair 1, 3

Additional Relevant Tests

• Complete blood count: Assess for anemia and total lymphocyte count (marker of immune function) 1
• Blood glucose/HbA1c: Essential for diabetic wound patients 1
• Kidney function tests: BUN/creatinine to assess protein metabolism and hydration status 1
• Electrolytes: Sodium, potassium, chloride, calcium, phosphorus 1
• Triglycerides: To monitor fat metabolism, especially if parenteral nutrition is being considered 1

Frequency of Monitoring

• Initial assessment: Complete panel at first evaluation
• Acute/critical patients: Daily monitoring may be required 1
• Stable patients: Measurements repeated 2-3 times per week 1
• Long-term follow-up: Monthly monitoring of key nutrients for chronic wound patients

Special Considerations

Patient-Specific Factors

• Diabetic foot ulcers: Additional focus on glycemic control markers and vitamin D, C, A, E, magnesium, zinc, and omega-3 fatty acid levels 3
• Pressure ulcers: Particular attention to protein markers and arginine/glutamine levels 1
• Small bowel disease/resection: More frequent monitoring of vitamin B12, zinc, and fat-soluble vitamins 1
• Patients on steroids: Monitor vitamin A status as supplementation may counteract steroid-induced healing impairment 2

Common Pitfalls

• Interpreting albumin in acute illness: Albumin is an acute phase reactant affected by inflammation, not just nutritional status 1
• Overlooking hydration status: Fluid shifts can affect laboratory values and wound healing 1
• Focusing only on macronutrients: Micronutrient deficiencies can significantly impair healing even when protein and calorie intake are adequate 3, 4
• Relying solely on BMI: Body mass index does not correlate well with wound complications; laboratory assessment is essential 1

Nutritional Screening Tools

Consider using validated nutritional screening tools alongside laboratory assessment:

• Nutritional Risk Screening 2002 (NRS-2002)
• Subjective Global Assessment (SGA)
• Modified Nutrition Risk in Critically Ill (mNUTRIC) for ICU patients 1

Laboratory assessment should be part of a comprehensive nutritional evaluation that includes anthropometric measurements, dietary intake assessment, and functional status to optimize wound healing outcomes.