respiratory failure

Medical Nutrition Therapy for Patients with Respiratory Failure

Introduction to Respiratory Failure

  • Definition: Respiratory failure is a condition in which the respiratory system fails to adequately exchange gases, leading to insufficient oxygen and/or excessive carbon dioxide.
  • Causes: Can be categorized into acute and chronic types.
    • Acute Causes:
    • Drug overdose affecting respiratory centers in the brain.
    • Acute Respiratory Distress Syndrome (ARDS), a condition where patients temporarily experience significant respiratory distress.
    • Chronic Conditions:
    • Chronic Obstructive Pulmonary Disease (COPD)
    • Cystic Fibrosis
  • Key Characteristics:
    • Hypoxemia (low oxygen levels in the blood).
    • Hypercarbia (high carbon dioxide levels in the blood).
    • Measurement through arterial blood gases (ABGs).

Respiratory Support for Patients in Respiratory Failure

  • Need for Respiratory Support: Patients in respiratory failure often require additional respiratory support, impacting their nutritional needs.
    • Types of Support:
    • Supplemental Oxygen.
    • Non-Invasive Ventilation (NIV).
      • CPAP (Continuous Positive Airway Pressure).
      • BiPAP (Bilevel Positive Airway Pressure).
    • Invasive Mechanical Ventilation (via endotracheal tube or tracheostomy).
Supplemental Oxygen
  • Indictions: Required for mild hypoxemia, conscious and stable patients; often used in conditions like pulmonary edema, pneumonia, or COPD.
  • Administration:
    • Nasal Cannula or Oxygen Mask.
    • Meals can be challenging due to fatigue and decreased oxygen saturation during eating.
    • Potential for tube feeding via nasogastric (NG) or nasojejunal tubes.
Non-Invasive Ventilation (NIV)
  • CPAP:
    • Delivers continuous pressure to maintain airway patency; commonly used for sleep apnea.
  • BiPAP:
    • Offers higher pressure during inhalation and lower during exhalation, supporting easier breathing out.
    • Masks may hinder oral intake; full face masks require an airtight seal for effectiveness.
    • Nutritional Challenges:
    • Patients may struggle to eat while wearing masks due to decreased oxygen saturation during meals.
    • Use of post-pyloric tubes may be necessary to reduce aspiration risks.
Invasive Mechanical Ventilation
  • Endotracheal Tube:
    • Inserted directly into the trachea, providing complete ventilatory support. Challenges include inability to swallow, making oral intake contraindicated.
  • Tracheostomy:
    • An opening made in the neck to assist breathing for long-term ventilation. Provides freedom for oral intake, allowing for enteral nutrition.
  • Nutrition Plan:
    • Enteral nutrition via NG or nasojejunal tube.
    • Uniform strategies for both types of ventilation, prioritizing timely initiation of nutrition.

Nutritional Assessment and Support

  • Metabolic Considerations:
    • Patients are often hypermetabolic and hypercatabolic.
  • Caloric Needs: Increased caloric and protein support tailored to the patient’s inflammatory status and metabolic state.
    • Recommendations include:
    • Small, frequent meals.
    • Nutrient-dense foods.
    • Oral nutrition supplements.
    • Resting before meals.

Enteral Nutrition for Ventilated Patients

  • Initiation Timing: Begin within 24-48 hours of admission to reduce muscle atrophy and prevent loss of respiratory muscle strength.
  • Protein Requirements: 1.2 to 2 grams of protein per kilogram of body weight.
  • Fluid Management: Monitor for fluid overload; ensure elevation of the head of bed to minimize aspiration risks.
  • Propofol Administration:
    • A sedative administered via IV that can provide additional caloric intake, necessitating adjustments to nutrition plans.
    • Example calculation for calories from Propofol provided in transcript.

Nutrition Calculation for Ventilated Patients

  • Indirect Calorimetry:
    • An ideal method to calculate energy needs; check if ventilators can measure Resting Energy Expenditure (REE).
  • Penn State Equations: Utilized for estimating calorie needs in ventilated patients. Utilize Mifflin St. Jeor equation for Resting Metabolic Rate (RMR).
    • Need for minute ventilation and maximum body temperature recorded in Celsius.
    • Special considerations for determining the appropriate Penn State equation version based on age and obesity status.
  • Example Calculations:
    • 82-year-old female post-surgery; BMI determined if obese to decide appropriateness of Penn State equation.
    • 55-year-old male with pneumonia calculated using appropriate equation.

Enteral Formula Selection and Recommendations

  • Standard Enteral Formulas: Generally recommended instead of specialty pulmonary formulas due to lack of evidence for superiority.
  • Considerations on Macronutrient Composition:
    • The impact of carbohydrate and fat percentages on carbon dioxide production discussed.
    • High-fat formulas can lead to gastric intolerance.

Transitioning to Oral Intake

  • Post-Extubation Protocol:
    • Speech therapy consultation critical for safe swallowing assessment.
    • Progressive diet tailored to patient's swallowing capability. Adjust nutritional support according to oral intake improvements.
    • Risk of aspiration while eating with tracheostomy; collaboration with speech therapists essential.

Conclusion

  • The management of nutritional therapy in patients with respiratory failure demands a multifaceted approach focusing on their specific respiratory support requirements, metabolic changes, and feeding strategies. Nutritionists must operate continuously with other disciplines to ensure safe and effective feeding methods are applied, adjusting plans based on patient progress and therapy outcomes.