For optimal healing capability, the patient’s blood sugar level should range between 100 and 200 mg/dL. Hyperglycemia causes red blood cells to be less deformable and increases blood viscosity, causing vascular stasis in the microcirculation. Glycosylated hemoglobin also has a higher affinity for oxygen. This impairs the delivery of oxygen to ischemic tissues. As a result, macrophage and granulocytes cannot function effectively against bacteria, and there is interference with collagen synthesis and angiogenesis. This leads to delayed secondary healing. Other Key Factors That Affect Wound Healing Malnutrition is fairly common in chronic ulcer patients. It accounts for up to 50 percent of medical/surgical patients and 60 percent of patients placed in nursing homes. Numerous studies have shown the relationship between specific nutrient deficiency and delayed wound healing, and between nutritional status and length of hospital stay. Protein, fats and carbohydrates are important in cell division as well as fuel sources in the repair process. Vitamins and trace elements work as co-factors in cell differentiation or collagen synthesis. It has been reported that the status of visceral proteins dictates the patient’s ability to heal wounds and mount an immune response. The visceral proteins that should be included in a nutritional assessment are serum albumin, total protein and serum transferrin (see the table above). Nutritional deficiencies can be associated with nausea, depression, poor social circumstance and chronic disease. It’s important to evaluate these patients critically and initiate adequate nutritional intervention. External factors, including pressure, edema and poor patient compliance, can also significantly affect the wound healing process. Shear force can destroy the fragile layer of epithelial cells of an open wound. Gross wound contamination by stool, saliva or urine makes the wound more susceptible for prolonged infection. Self-inflicted chronic wounds or Munchausen’s syndrome may be more common than traditionally thought, and may require psychiatric consultation in order to achieve optimal wound healing. Final Notes There are many factors that prevent wounds from healing. Those factors must be identified and if possible, corrected, for healing to occur. Even before we consider adjunctive therapy, we need to evaluate potential underlying causes of chronic ulcers in order to achieve optimal healing. It takes the simple practice of good history taking, adding simple lab works, preparing the optimal wound base and making adequate referrals for individual patients. Dr. Morita is a first year resident at the University of Texas Health Science Center, Division of Podiatry. Dr. Steinberg (pictured) is an Assistant Professor in the Department of Orthopaedics/Podiatry Service at the University of Texas Health Science Center.
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