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Medical Nutrition Therapy in Pulmonary Disease. Malnutrition and the Pulmonary System. Malnutrition impairs Respiratory muscle function Ventilatory drive Response to hypoxia Pulmonary defense mechanisms. Effects of Malnutrition in Pts without Lung Disease.
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Malnutrition and the Pulmonary System Malnutrition impairs • Respiratory muscle function • Ventilatory drive • Response to hypoxia • Pulmonary defense mechanisms
Effects of Malnutrition in Pts without Lung Disease • Respiratory muscle strength ↓ by 37% • Maximum voluntary ventilation ↓by 41% (1) • Vital capacity (lung volume)↓ 63% (1) • Diaphragmatic muscle mass ↓ to 60% of normal in underweight patients who died of other ailments (2) • Aurora N, Rochester, D. Am Rev Respir Dis 126:5-8, 1982 • Aurora N, Rochester D. J Appl Physiol: Respirat Environ Exercise physiol 52:64-70, 1982
Effects of Malnutrition in Pts with Pulmonary Disease • Decreased cough and inability to mobilize secretions • Atelectasis and pneumonia • Prolonged mechanical ventilation and difficulty weaning with prolonged ICU stay
Effects of Malnutrition in Pts with Pulmonary Disease • Altered host immune response and cell-mediated immunity • Contributes to chronic or repeated pulmonary infections • Decreased surfactant production • Decreased lung elasticity • Decreased ability to repair injured lung tissue
Chronic Pulmonary Disorders • Bronchopulmonary displasia • Cystic fibrosis • Tuberculosis • Bronchial asthma • Chronic obstructive pulmonary disease (COPD)
Acute Pulmonary Disorders • Pulmonary aspiration • Pneumonia • Tuberculosis • Cancer of the lung • Acute respiratory distress syndrome • Pulmonary failure
Adverse Effects of Lung Disease on Nutritional Status Increased energy expenditure • Increased work of breathing • Chronic infection • Medical treatments (e.g. bronchodilators, chest physical therapy
Adverse Effects of Lung Disease on Nutritional Status Reduced intake • Fluid restriction • Shortness of breath • Decreased oxygen saturation when eating • Anorexia due to chronic disease • Gastrointestinal distress and vomiting
Adverse Effects of Lung Disease on Nutritional Status Additional limitations • Difficulty preparing food due to fatigue • Lack of financial resources • Impaired feeding skills (for infants and children) • Altered metabolism
Bronchopulmonary Dysplasia: Pathophysiology • Chronic lung condition in newborns that often follows respiratory distress syndrome (RDS) and treatment with oxygen • Characterized by broncheolar metaplasia and interstitial fibrosis • Occurs most frequently in infants who are premature or low birth weight
BPD: Signs and Symptoms • Hypercapnea (CO2 retention) • Tachypnea • Wheezing • Dyspnea • Recurrent respiratory infections • Cor pulmonale (right ventricular enlargement of the heart)
Growth Failure in BPD • Increased energy needs • Inadequate dietary intake • Gastroesophageal reflux • Emotional deprivation • Chronic hypoxia
Goals of Nutritional Management in BPD • Meet nutritional needs • Promote linear growth • Develop age-appropriate feeding skills • Maintain fluid balance
Energy Needs in BPD • REE in infants with BPD is 25-50% higher than in age-matched controls • Babies with growth failure may have needs 50% higher • Energy needs in acute phase (PN, controlled temperature) 50-85 kcals/kg • Energy needs in convalescence (oral feeds, activity, temperature regulation) as high as 120-130 kcals/kg
Protein Needs in Babies with BPD • Protein: within advised range for infants of comparable post-conceptional age • As energy density of the diet is increased by the addition of fat and carbohydrate, protein should still provide 7% or more of total kcals
Macronutrient Mix in BPD • Fat and carbohydrate should be added to formula only after it has been concentrated to 24 kcals/oz to keep protein high enough • Fat provides EFA and energy when tolerance for fluid and carbohydrate is limited • Excess CHO increases RQ and CO2 output
Fluid in BPD • Infants with BPD may require fluid restriction, sodium restriction, and long term treatment with diuretics • Use of parenteral lipids or calorically dense enteral feeds may help the infant meet energy needs
Mineral Needs in BPD • Often driven by the baby’s premature status • Lack of mineral stores as a result of prematurity (iron, zinc, calcium) • Growth delay • Medications: diuretics, bronchodilators, antibiotics, cardiac antiarrhythmics, corticosteroids associated with loss of minerals including chloride, potassium, calcium
Vitamin Needs in BPD • Interest in antioxidants, including vitamin A for role in developing epithelial cells of the respiratory tract • Provide intake based on the DRI, including total energy, to promote catchup growth
Feeding Strategies in BPD • Calorically dense formulas or boosted breast milk (monitor fluid status and urinary output) • Small, frequent feedings • Use of a soft nipple • Nasogastric or gastrostomy tube feedings
Feeding Strategies in Gastroesophageal Reflux • Thickened feedings (add rice cereal to formula) • Upright positioning • Medications like antacids or histamine H2 blockers • Surgical fundoplication
Long Term Feeding Problems in BPD • History of unpleasant oral experiences (intubation, frequent suctioning, recurrent vomiting) • History of non-oral feedings • Delayed introduction of solids • Discomfort or choking associated with eating solids • Infants may tire easily while breast-feeding or bottle feeding • May require intervention of interdisciplinary feeding team
Cystic Fibrosis • Inherited autosomal recessive disorder • 2-5% of the white population are heterozygous • CF incidence of 1:2500 live births • 30,000 people treated at CF centers in the U.S. • Survival is improving; median age of patients has exceeded 30 years
Cystic Fibrosis • Epithelial cells and exocrine glands secrete abnormal mucus (thick) • Affects respiratory tract, sweat, salivary, intestine, pancreas, liver, reproductive tract
Diagnosis of Cystic Fibrosis • Neonatal screening provides opportunity to prevent malnutrition in CF infants • Sweat test (Na and Cl >60 mEq/L) • Chronic lung disease • Failure to thrive • Malabsorption • Family history
Nutritional Implications of CF • Infants born with meconium ileus are highly likely to have CF • 85% of persons with CF have pancreatic insufficiency • Plugs of mucus reduce the digestive enzymes released from the pancreas causing maldigestion of food and malabsorption of nutrients
Nutritional Implications of CF • Decreased bicarbonate secretion reduces digestive enzyme activity • Decreased bile acid reabsorption contributes to fat malabsorption • Excessive mucus lining the GI tract prevents nutrient absorption by the microvilli
Gastrointestinal Complications of CF • Bulky, foul-smelling stools • Cramping and intestinal obstruction • Rectal prolapse • Liver involvement • Pancreatic damage causes impaired glucose tolerance (50% of adults with CF) and development of diabetes (15% of adults with CF)
Nutritional Care Goals • Control malabsorption • Provide adequate nutrients for growthor maintain weight for height or pulmonary function • Prevent nutritional deficiencies
Common Treatments • Pancreatic enzyme replacement • Adjust macronutrients for symptoms • Nutrients for growth • Meconium ileus equivalent: intestinal obstruction (enzymes, fiber, fluids, exercise, stool softeners)
Pancreatic Enzyme Replacement • Introduced in the early 1980s • Enteric-coated enzyme microspheres withstand acidic environment of the stomach • Release enzymes in the duodenum, where they digest protein, fat and carbohydrate
Pancreatic Enzyme Replacement Dosage depends on • Degree of pancreatic insufficiency • Quantity of food eaten • Fat, protein, and carbohydrate content of food eaten • Type of enzymes used
Pancreatic Enzyme Replacement • Enzyme dosage limited to 2500 lipase units per kilogram of body weight per meal • Adjusted empirically to control gastrointestinal symptoms, including steatorrhea, and promote growth • Fecal fat or nitrogen balance studies may help to evaluate the adequacy of enzyme supplementation
Distal Intestinal Obstruction Syndrome • AKA recurrent intestinal impaction • Occurs in children and adults • Prevention includes adequate enzymes, fluids, dietary fiber, and regular exercise • Treatment involves stool softeners, laxatives, hyperosmolar enemas, intestinal lavage
Estimation of Energy Needs in CF • Use WHO equations to estimate BMR • Multiply by activity coefficient + disease coefficient • TEE – BMR X (AC + DC) • Disease coefficient is based on lung function
Disease Coefficient in CF • Normal lung function = 0.0 • Moderate lung disease = 0.2 • FEV1 40-79% of that predicted • Severe lung disease = 0.3 • FEV1 <40% of that predicted • FEV = forced expiratory volume
Example Equation TEE in CF • Male patient 22 years old, weight 54 kg, relatively sedentary • FEV1 is 60% of predicted (moderate lung disease) • TEE = BMR X (1.5 + 0.2) • TEE = [(15.3 (54) + 679] X 1.7 • TEE = 2559 kcals
Calculate the Daily Energy Requirement (DER) • Takes into account steatorrhea • Pancreatic sufficiency: TEE = DER • Pancreatic sufficiency is Coefficient of fat absorption >93% of intake • Pancreatic insufficiency: DER = TEE (0.93/CFA) • CFA is a fraction of fat intake based on stool collections
Calculation of DER in CF • 72-hour fecal fat collections reveals that CFA is 78% of intake • DER = TEE X (.93/CFA) • = 2559 X (0.93/.78) • = 2559 X 1.19 • DER = 3045 kcals/day
Protein in CF • Protein needs are increased in CF due to malabsorption • If energy needs are met, protein needs are usually met by following typical American diet (15-20% protein) or use RDA
Fat Intake in CF • Fat intake 35-40% of calories, as tolerated • Helps provide required energy, essential fatty acids and fat-soluble vitamins • Limits volume of food needed to meet energy demands and improves palatability of the diet • EFA deficiency sometimes occurs in CF patients despite intake and pancreatic enzymes