nutrition & diet therapy, 7 th edition energy- & protein-modified diets for metabolic &...

Nutrition & Diet Therapy, 7th Edition

Energy- & Protein-Modified Diets for Metabolic & Respiratory

Stress

Chapter 24


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


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


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

SwellingRedness

HeatPain


Inflammatory Response


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


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 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.

24-2 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 1.0-2.0 grams per kg body weight daily (burn patients require more, 2-2.5 g/Kg, due to significant protein losses)

• Glutamine & arginine supplementation may be indicated, studies still being done.


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 1-1.5 grams per kg daily– Frequent assessment of nutritional needs necessary– Micronutrients: 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


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 & 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



• 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



• 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



• 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


• Mechanical ventilation controls the rate & amount of O2 supplied to a person’s airways



• 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 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 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, 7 th edition energy- & protein-modified diets for metabolic &...

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