What is the management of respiratory failure?

Management of Respiratory Failure

The management of respiratory failure requires a structured approach starting with appropriate oxygen therapy targeting specific saturation goals (94-98% for most patients, 88-92% for those at risk of hypercapnia), followed by escalation to non-invasive or invasive ventilation based on clinical response and underlying etiology. 1

Initial Assessment and Oxygen Therapy

Oxygen Therapy Initiation

• For patients without risk of hypercapnic respiratory failure:

  • Start with nasal cannula at 1-2 L/min or simple face mask at 5-10 L/min
  • Target SpO₂ 94-98% 1

• For patients with COPD or risk of hypercapnic respiratory failure:

  • Use 24% Venturi mask at 2-3 L/min or 28% Venturi mask at 4 L/min
  • Target SpO₂ 88-92% to prevent respiratory acidosis 1

• For severe hypoxemia:

  • Use reservoir mask at 15 L/min 1
  • Obtain arterial blood gas (ABG) measurement to assess oxygenation, ventilation, and acid-base status
  • Reassess within 30-60 minutes after oxygen initiation 1

Non-Invasive Ventilation (NIV)

NIV should be considered for patients with:

• COPD exacerbation with respiratory acidosis (pH <7.35)
• Chest wall deformity
• Neuromuscular disorders
• Cardiogenic pulmonary edema unresponsive to CPAP 2, 1

NIV Protocol

1. Decide management plan if NIV fails, after discussion with senior medical staff
2. Determine appropriate setting (ICU, HDU, or respiratory ward)
3. Consider informing ICU
4. Explain NIV to the patient
5. Select appropriate mask and set up ventilator
6. Initial settings for hypercapnic respiratory failure:
   • Inspiratory pressure: 17-35 cmH₂O
   • Expiratory pressure: 7 cmH₂O
7. Monitor with pulse oximetry
8. Add oxygen if SpO₂ <85%
9. Check arterial blood gases at 1-2 hours
10. If no improvement in PaCO₂ and pH after 4-6 hours on optimal settings, consider alternative management 2, 1

High-Flow Nasal Oxygen (HFNO)

HFNO may be beneficial in:

• Initial management of hypoxemic respiratory failure
• Postextubation management

Benefits compared to conventional oxygen therapy (COT):

• Modest reduction in hospital-acquired pneumonia (ARD, −4.7%)
• May improve dyspnea and patient comfort
• May reduce reintubations slightly in postextubation patients 2

Benefits compared to NIV in postextubation management:

• Large reduction in skin breakdown (ARD, −19.7%) 2

Invasive Mechanical Ventilation

Indications for invasive ventilation:

• Severe hypoxemic failure despite non-invasive support
• Respiratory acidosis despite maximal medical treatment
• Failure of NIV
• Inability to protect airway 1, 3

Ventilation strategies:

• Lung-protective ventilation with low tidal volumes
• Appropriate PEEP
• Consider permissive hypercapnia 3

Advanced Strategies for Refractory Cases

For patients with severe respiratory failure not responding to conventional therapies:

• Prone positioning
• Recruitment maneuvers
• Airway pressure release ventilation
• High-frequency oscillatory ventilation 3

Extracorporeal Membrane Oxygenation (ECMO)

Consider ECMO for:

• Life-threatening respiratory failure unresponsive to conventional therapy
• Potentially reversible condition
• No contraindications to anticoagulation 4, 5

ECMO provides adequate tissue oxygen delivery without causing iatrogenic damage associated with high mechanical ventilation pressures or high FiO₂ 4

Monitoring and Adjustments

• Continuously monitor oxygen saturation, respiratory rate, and heart rate
• For COPD patients:
  • Reduce oxygen if SpO₂ exceeds 92%
  • Increase oxygen if SpO₂ falls below 88%
  • Check arterial blood gases 30-60 minutes after starting oxygen therapy 1

Common Pitfalls to Avoid

• Overlooking the need for ABG assessment
• Delayed escalation of therapy when conventional oxygen is failing
• Excessive oxygen therapy in patients at risk of hypercapnia
• Failing to recognize patients requiring NIV or invasive ventilation 1
• Rapid correction of PaCO₂ in patients with severe acidosis 1

Special Considerations

• Patients with prior episodes requiring NIV or mechanical ventilation should have an alert card specifying their target saturation range
• Position patient in semi-recumbent position (30-45° head elevation) to reduce work of breathing
• Manage pain appropriately while recognizing risks of respiratory depression 1
• Treat underlying causes of respiratory failure (infection, pulmonary embolism, etc.)

By following this structured approach to respiratory failure management, clinicians can optimize oxygenation and ventilation while minimizing complications and improving patient outcomes.