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Skin, Wounds and Nutrition Part 3. Friction Forces at the Skin. Cause skin abrasions, damaging the stratum corneum Pulls at the skin producing shear in deeper tissue layers. Shear Forces. Causes tissue layers to slide and pull against each other
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Friction Forces at the Skin • Cause skin abrasions, damaging the stratum corneum • Pulls at the skin producing shear in deeper tissue layers
Shear Forces • Causes tissue layers to slide and pull against each other • Disassociates connective tissue and blood vessels
Friction and Shear • Provide a slippery bed surface to prevent skin abrasion and tearing of deeper tissues
Heat • Remove excess heat to reduce the oxygen and nutrient demands of damaged/healing tissue
Effects of Heat on Damaged Tissue • Increases metabolism, nutrient and oxygen demand, 10% per degree C • Accelerates ischemic tissue death by oxygen and nutrient starvation
Sources of Excess Moisture • Insensible transpiration • Perspiration • Urinary incontinence
Excess Skin Moisture • Weakens the stratum corneum up to 95% • Increases liquid surface tension causing high skin friction • Causes maceration by dissolving connective tissue fibers
The RD and Nutrition Important Components to Wound Healing
The Healing Wound Wounds heal when protein stores, energy stores and anabolic stimuli are adequate to support the healing process
The Bottom Line • Many patients with wounds will develop protein calorie malnutrition • Malnourished patients upon hospital admission are more likely to develop PUs • UWL in residents in LTC was associated with 74% greater likelihood of developing PU (Thomas)
Adverse Effects of PCM on the Health Care System • Reduces quality of life • Decreases response to tx interventions • Increases morbidity and mortality • Drains staff emotionally • Increases paperwork and documentation • Costs more to care for a patient with PCM
Clinically Evident Manifestations of PCM • Listlessness, apathy, weakness--all exacerbated by anemia • Diminished functioning of diaphragm and thoracic musculature--contributing to respiratory compromise • Decreased skin turgor, muscle wasting, peripheral edema, glossitis, hair loss or changes in hair luster
Malnutrition • Defined as a pathologic state resulting from a relative or absolute deficiency • Clear correlation between malnutrition and wound healing failure • Can occur in both obesity and underweight • PCM most common form of malnutrition in America
Where to Begin • Examine those with low body weight or extremely obese • Any patient with UWL at any BMI • Low serum albumin • Dehydration
Underweight • No protection from fat • Recent weight loss • Considered <90% IBW
Obesity • Fat is poorly vascularized • Excessive weight placed on bony prominences • More likely to have moisture between folds • Defined as > 130% IBW
Complications of UWL • 10% weight loss increases wound complications • Increases risk of developing pressure ulcer at any BMI • Increased urinary losses of zinc
Managing Weight is No. 1 • Identify causes for weight changes • physiological • psychological • Educate patient on the importance of weight maintenance and maintenance of LBM • Consider pharmacological interventions
Complications Relative to Loss of LBM Source Demling,R. Stasik, L, Zagoren, A. Protein-energy malnutrition and wounds: nutritional intervention. Curative Health Services 11/00
Effects of Losses in LBM • <10%--wound healing has priority for any protein substrate • >10%--the stimulus to restore LBM competes with the wound for protein • >20%, correction of LBM takes precedence • Wound healing stops
Lab Values • Serum Transferrin < 170 mg/dL • Prealbumin < 16 mg/dL • Serum Albumin < 3.5 mg/dL (w/normal hydration status • Hemoglobin < 12 g/dL • Hematocrit < 33%
Lab Values--cont. • Serum Cholesterol < 160 mg/dL • Total Lymphocyte Count < 1800/mmm • Serum Osmolality > 295 mOsm/L • BUN/Creatinine > 10:1
Prealbumin (Transthyretin) • Half life is about 2 days • Smaller serum pool • Binds and transports • Is affected by inflammation • Less affected by hydration status • Used to monitor current nutrition status
Albumin • Half life is about 21 days • Common index of visceral proteins • A carrier protein • Formed in the liver • Affected by hydration as helps maintain normal water distribution • Used to monitor long term stores
Cholesterol • Are cholesterol lowering drugs being used? • May indicate malnutrition, especially in those > 60 years of age
Total Lymphocyte Count • Lymphocytes account for 20-40% of WBC • Measures immunocompetence • May be unable to mount effective immune response if low • Not an appropriate indicator for critical care patients, those with known immune problems or those with infections