© 2007 Thomson - Wadsworth Chapter 16 Nutrition in Metabolic & Respiratory Stress.

© 2007 Thomson - Wadsworth

Chapter 16

Nutrition in Metabolic & Respiratory Stress

© 2007 Thomson - Wadsworth

Body’s Response to Stress & Injury

• Stress response InfectionBurnsFracturesSurgeryExtensive bleeding

• Body focuses on immediate survival

• Nutrients are mobilized from storage

• Heart rate and respiration increase

• Blood pressure rises

© 2007 Thomson - Wadsworth

Hormonal Response to Stress

• Epinephrine & norepinephrineStimulate heart

muscleAlter blood flow rateRaise basal

metabolism

• GlucagonReleases nutrients

from storage

• Cortisol Enhances protein

degradation

• Aldosterone & antidiuretic hormoneHelp maintain blood

volumeStimulate kidneys to

reabsorb sodium & water

© 2007 Thomson - Wadsworth

The Inflammatory Response

• Serves toContain & destroy

infectious agentsPrevent further

tissue damage

• Dilation of arterioles• Constriction of

venules

• Classic signsSwellingRednessHeatPain

© 2007 Thomson - Wadsworth

© 2007 Thomson - Wadsworth

Nutrition Treatment

• ProblemsHypermetabolism &

negative nitrogen balance

• Wasting

Hyperglycemia & insulin resistance

• Increases infection risk

• Diet goalsPreserve lean tissuesMaintain immune

defensesPromote healing

• Need to balance overfeeding & underfeeding

© 2007 Thomson - Wadsworth

Estimating Requirements

• EnergyHarris-Benedict

equation (BEE)

• Protein1.0-2.0 g/kg

• Carbohydrates: 70% of kcalories

• Lipids: 40% of kcalories

• Vitamins & mineralsMay have

increased needs

© 2007 Thomson - Wadsworth

© 2007 Thomson - Wadsworth

Approaches to Nutrition Care

• Initial care: maintain fluid & electrolyte balance

• May need enteral and/or parenteral support

• High-kcalorie, high-protein dietTake care not to overfeedReassess frequently

© 2007 Thomson - Wadsworth

Nutrition & Respiratory Stress

• Respiratory stressReduced oxygenIncreased carbon

dioxide• Labored breathing

Interferes with food intake

Weight loss & malnutrition

© 2007 Thomson - Wadsworth

© 2007 Thomson - Wadsworth

Chronic Obstructive Pulmonary Disease (COPD)

© 2007 Thomson - Wadsworth

Chronic Obstructive Pulmonary Disease (COPD)

• Persistent obstruction of airflow Chronic bronchitis

• Excessive mucus secretions

• Productive cough Emphysema

• Breakdown of lung’s elastic structure

• Dyspnea

• Causes Smoking Chronic respiratory

infections Occupational exposure to

dusts or chemicals Genetic susceptibility

• Goals Improve food intake Maintain healthy weight Prevent muscle loss Improve exercise

endurance

© 2007 Thomson - Wadsworth

Treatment

• Small, frequent meals

• Adequate fluids• Liquid supplements• Exercise plan

© 2007 Thomson - Wadsworth

Respiratory Failure

• Gas exchange between air & blood is greatly impaired

• ConsequencesHypoxemiaHypercapnia HypoxiaAcidosisCyanosis

• CausesObstruction Weakness or

paralysis of musclesEmbolusToxic substancesSevere trauma &

infection

© 2007 Thomson - Wadsworth

Treatment

• Support lung function• Correct underlying disorder• Careful monitoring of fluid• Medications

© 2007 Thomson - Wadsworth

Treatment

• Chronic lung diseaseOxygen therapy

• Acute respiratory distress syndrome (ARDS)Mechanical ventilation

© 2007 Thomson - Wadsworth

Nutrition Care

• Individualize according to patient’s condition

• Enough energy & protein to support lung function without overtaxing the respiratory system

© 2007 Thomson - Wadsworth

Nutrition in Practice

Multiple Organ Failure

© 2007 Thomson - Wadsworth

Multiple Organ Failure

• Cause of death in ½ of ICU patients

• A failure of two or more organ systems

• Chemical mediators can cause systematic response syndrome (SIRS), leading to shock & organ failure

• Organs Lungs Liver Kidneys GI tract

• Causes Acute respiratory

failure Trauma Sepsis Burns Extensive surgery Pancreatitis

© 2007 Thomson - Wadsworth

© 2007 Thomson - Wadsworth

© 2007 Thomson - Wadsworth

Risk Factors

• Age over 55• Prior chronic

illness• Persistent SIRS• Major infection• Blood

transfusions

• Severity of tissue injury

• Length of time between injury & arrival at hospital

• Malnutrition

© 2007 Thomson - Wadsworth

Treatment

• Mechanical ventilation

• Fluid & electrolytes

• Medications to sustain or increase cardiac output & blood pressure

• Hemofiltration or dialysis

• Antibiotic therapy for infection

• Enteral & parenteral nutrition