Systemic Factors, Nutrition, and Comorbid Conditions
Why systemic factors decide outcomes
A wound cannot heal faster than its blood supply, oxygen delivery, and substrate availability allow. Candidates must connect local findings to systemic disease: diabetes (hyperglycemia impairs leukocyte function and collagen synthesis), peripheral arterial disease (perfusion), venous insufficiency (edema and ambulatory venous hypertension), chronic kidney disease, anemia, obesity, immunosuppression, and polypharmacy.
Nutrition essentials
Screen every patient with a validated tool and refer to a dietitian when intake is poor, weight is falling, or wounds are large or multiple. Key measures include unintentional weight loss, body mass index, and intake history. For adults with pressure injuries, common recommendations are roughly 30–35 kcal/kg/day and 1.25–1.5 g/kg/day of protein, with adequate fluid. Micronutrients such as vitamin C and zinc support healing, but high-dose supplementation without documented deficiency has not been shown to accelerate healing - a frequent distractor.
Laboratory interpretation
Albumin and prealbumin fall with inflammation, so they reflect inflammatory state as much as nutrition. Do not use a single value to diagnose malnutrition. HbA1c and glucose indicate glycemic control; CBC and renal function inform healing capacity and medication safety.
Medications and habits
Corticosteroids, immunosuppressants, and some chemotherapeutics impair healing. Anticoagulants do not stop healing but affect debridement planning and bleeding risk. Smoking and uncontrolled edema are modifiable and should be addressed explicitly.
Traps
- Ordering zinc or vitamin C to "speed healing" in a well-nourished patient.
- Diagnosing malnutrition from a low albumin alone.
- Applying compression before assessing arterial perfusion.
- Ignoring substance use, food insecurity, or the ability to obtain and prepare food.
Rule of thumb
If a wound is stalled and local care is appropriate, look up from the wound: glucose, perfusion, protein intake, edema, and medications are the usual culprits.