1. Energy- & Protein-Modified Diets for Metabolic & Respiratory Stress
Chapter 24
Nutrition & Diet Therapy, 7th Edition

2. Stress in the Body
Body’s response to severe stress can threaten survival
Stress increases nutritional needs considerably—increasing risk of malnutrition
Metabolic stress: disruption of body’s internal chemical environment
Respiratory stress: characterized by inadequate oxygen supply & excessive carbon dioxide in blood & tissues
Both types of stress can lead to hypermetabolism, wasting & life-threatening complications
Nutrition & Diet Therapy, 7th Edition

3. I. Body’s Response to Stress & Injury
Stress response: non-specific response of the body to variety of stressors (ex. infection, fractures, surgery, etc.)
Metabolic processes focus on immediate survival
Energy nutrients mobilized from storage & made available in the blood
Energy is diverted from non-essential processes (like growth…)
Heart & respiratory rates increase to deliver oxygen & nutrients to cells
Long-term stress results in damage to body processes due to diversion of energy, nutrients to organs needed for survival
Nutrition & Diet Therapy, 7th Edition

4. Nutrition & Diet Therapy, 7th Edition

5. Body’s Response to Stress & Injury
Inflammatory response
Quick, non-specific immune system response to infection or tissue injury
Contains & destroys infectious agents & their agents; prevents further tissue damage
Classic Signs of Localized Inflammation
Swelling
Redness
Heat
Pain
Nutrition & Diet Therapy, 7th Edition

6. Inflammatory Response
Nutrition & Diet Therapy, 7th Edition

7. Body’s Response to Stress & Injury
Systemic effects of inflammation
Acute-phase response: changes in body chemistry resulting from inflammation, infection or severe injury
Release of acute-phase proteins & blood clotting proteins
Decreased plasma concentrations of albumin, iron & zinc
Muscle catabolism & negative nitrogen balance
Elevated metabolic rate, increased numbers of neutrophils
Lethargy, anorexia
Fever
Systemic inflammatory response syndrome and sepsis-long term
Whole-body response to unresolved inflammation or infection
Increased heart rate & respiratory rate
Elevated WBC levels
Critical elevation of body temperature
Complications
Excessive fluid retention & tissue edema
Low blood pressure
Impaired blood flow
Can lead to shock—affecting functioning of multiple organs
Nutrition & Diet Therapy, 7th Edition

8. II. Nutrition Treatment in Acute Stress
Determining nutritional requirements
Major metabolic changes in metabolic stress
Hypermetabolism
Negative nitrogen balance
Hyperglycemia
Insulin resistance
Feeding patient during acute stress presents challenges
Overfeeding increases risks of refeeding syndrome
Underfeeding worsens negative nitrogen balance & increases lean tissue losses
Refeeding syndrome—develops when malnourished individual is aggressively fed; associated with fluid & electrolyte imbalances; hyperglycemia
Nutrition & Diet Therapy, 7th Edition

9. Nutrition Treatment in Acute Stress
Determining nutritional requirements (con’t)
Nutritional assessment
Complicated by fluid imbalances & lab data
Amounts of pro & E to provide are controversial (p.660, T provide guidelines)
Assortment of medical conditions that cause metabolic stress makes each situation unique
Clinicians must observe patient’s responses & readjust nutrient intakes as necessary
Estimation of protein needs
Intakes recommended during acute stress are higher than DRI values
Variable needs, but range between grams per kg body weight daily (burn patients require more, g/Kg, due to significant protein losses)
Glutamine & arginine supplementation may be indicated, studies still being done.
Nutrition & Diet Therapy, 7th Edition

10. Nutrition Treatment in Acute Stress
Determining nutritional requirements (con’t)
Carbohydrate & fat
Bulk of energy needs are supplied by carbohydrate & fat
50-60% total kcalorie intake from carbohydrate sources
Fat intake (if patient does not have hypertriglyceridemia) may be grams per kg daily
Frequent assessment of nutritional needs necessary
Micronutrients: h need for B,C, & A vits, Zn
Approaches to nutrition care
Initial care—maintain fluid & electrolyte balances w/IV
Once feeding begins—combination of methods to meet nutritional needs
Nutritional support as warranted
Enteral nutrition preferred
Parenteral nutrition if adequate nutrient intakes cannot be provided from enteral feedings alone
Nutrition & Diet Therapy, 7th Edition

11. III. Nutrition & Respiratory Stress
Chronic obstructive pulmonary disease (COPD)
Group of conditions characterized by persistent obstruction of airflow through the lungs
Chronic bronchitis
Emphysema
Both conditions reduce capacity of lungs to maintain normal oxygen & carbon dioxide levels in the blood
Shortness of breath (dyspnea) occurs
May lead to respiratory or heart failure
4th leading cause of death in U.S.
Nutrition & Diet Therapy, 7th Edition

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13. Nutrition & Respiratory Stress
COPD (con’t)
Debilitating condition
Dyspnea generally worsens as condition progresses
Results in dramatic reductions in physical activity & quality of life
Associated with other chronic illnesses, anxiety, depression & psychological distress
Causes
Smoking tobacco is primary risk
Genetic susceptibility contributes to development, especially in patients with early-onset COPD
Nutrition & Diet Therapy, 7th Edition

14. Nutrition & Respiratory Stress
COPD (con’t)
Treatment
Primary objectives of treatment: prevent disease from progressing & relieve major symptoms
Smoking cessation
Influenza & pneumonia vaccinations
Medications
Bronchodilators
Corticosteroids
Nutrition
Promote maintenance of healthy body weight & prevent muscle loss
Improve food intake
Small, frequent meals
Adequate fluid intake
High-kcalorie, high-protein diet if undernourished
Liquid supplements to improve weight gain or exercise endurance
E-restricted diet for gradual weight loss if overweight or obese
Specialized formulas
Incorporating exercise program
Nutrition & Diet Therapy, 7th Edition

15. Nutrition & Respiratory Stress
Respiratory failure
Gas exchange between air & circulating blood becomes greatly impaired
May develop from chronic disease (ex., COPD) or acute respiratory failure
Various factors affecting lung function may contribute to cause
Acute respiratory distress syndrome (ARDS)
Acute form of respiratory failure, life threatening
Commonly triggered by severe trauma or infection
Nutrition & Diet Therapy, 7th Edition

16. Nutrition & Respiratory Stress
Respiratory failure (con’t)
Consequences
Low blood levels of oxygen (hypoxemia) & excessive carbon dioxide in blood (hypercapnia)
Acidosis
Increased respiratory rate
Cyanosis (blue skin), other symptoms
Inadequate oxygen supply to tissues (hypoxia)
Treatment
Focuses on supporting lung function & correction of underlying disorder
Treatment plan depends on specific disorder
Oxygen therapy
Mechanical ventilation
Monitoring & supporting fluid balance
Diuretics
Medications to treat infection, keep airways open, relieve inflammation
Nutrition & Diet Therapy, 7th Edition

17. Mechanical ventilation controls the rate & amount of O2 supplied to a person’s airways
Nutrition & Diet Therapy, 7th Edition

18. Nutrition & Respiratory Stress
Respiratory failure (con’t)
Nutrition therapy
Individualized, based on patient’s condition
Provide enough E & protein to support lung function; increased cal, but not excessive as this generates extra CO2 and may increase respiratory problems.
Fluid restrictions to help reduce pulmonary edema
Enteral feeding preferred over parenteral nutrition
Nutrition support
Tube feedings are used if intestinal tract is functional
Intestinal feeding preferred over gastric
Nutrient-dense formula (2 kcalories per mL, less fld. needed)
Parenteral nutritional support may be necessary if risk of aspiration is too high to continue enteral feedings
Nutrition & Diet Therapy, 7th Edition

19. Nutrition in Practice—Multiple Organ Failure
Also referred to as multiple organ dysfunction syndrome
Late stage of severe illness or injury that results from severe inflammatory response
Failure of 2 or more of body’s organ systems
Involves lungs, liver, kidneys, GI tract
Involvement of 3 or more organs is associated with fatality rate of almost 100%
Cause
Systemic inflammatory response syndrome (SIRS)
Normal adaptive response to severe insult
Can progress to shock, resulting in impairment of numerous organ systems
Risk Factors: Age, Severity of SIRS, Infection, Blood transfusion
Nutrition & Diet Therapy, 7th Edition

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22. Nutrition in Practice—Multiple Organ Failure
Treatment
Lung support
Fluid resuscitation
Support of heart & blood vessel function
Kidney support
Reversal or prevention of infection
Nutrition support
Nutrition & Diet Therapy, 7th Edition