What is the step-by-step approach to managing acute respiratory failure?

Step-by-Step Approach to Acute Respiratory Failure

The management of acute respiratory failure requires prompt recognition, assessment of severity, and implementation of a structured approach targeting the underlying cause while supporting oxygenation and ventilation.

Initial Assessment and Management

• Perform immediate clinical evaluation focusing on work of breathing, mental status, and vital signs to determine severity of respiratory failure 1
• Obtain arterial blood gas analysis to classify the type of respiratory failure (Type I: hypoxemic, Type II: hypercapnic) 1
• Position the patient appropriately - semi-recumbent position (30-45° head elevation) if hemodynamically stable, or lateral position if unconscious to maintain airway patency 2
• Document an individualized treatment plan at the start, including measures to be taken if initial therapy fails 1
• Obtain chest radiography to identify potential causes or complications, but do not delay treatment in severe cases 1

Oxygen Therapy

• Administer controlled oxygen therapy targeting saturation of 88-92% in all causes of acute hypercapnic respiratory failure 2, 1
• Entrain oxygen as close to the patient as possible to optimize delivery 2
• Monitor oxygen saturation continuously for at least 24 hours after initiating treatment 2
• Recheck arterial blood gases 1-2 hours after starting oxygen therapy to ensure adequate oxygenation without worsening hypercapnia 1

Non-Invasive Ventilation (NIV)

• Initiate NIV when pH <7.35 and pCO2 >6.5 kPa persist despite optimal medical therapy, as this reduces mortality and need for intubation in appropriate patients 1
• Consider NIV for patients with dyspnea and/or persistent hypoxemia despite oxygen therapy 2
• Select appropriate interface (mask) based on patient comfort and facial anatomy, ensuring proper fit to minimize leaks 2
• Start with low pressures (e.g., IPAP 10-12 cmH2O, EPAP 4-5 cmH2O) and gradually increase as tolerated 2
• Both pressure support and pressure control modes are effective; use only ventilators specifically designed for NIV 2
• Measure arterial blood gases after 1-2 hours of NIV and again after 4-6 hours if the earlier sample showed little improvement 2
• If no improvement in PaCO2 and pH after 4-6 hours despite optimal ventilator settings, consider discontinuing NIV and evaluate for invasive ventilation 2
• Provide NIV for as many hours as possible during the first 24 hours, allowing breaks for medications, meals, and physiotherapy 2

High-Flow Nasal Oxygen (HFNO)

• Consider HFNO rather than NIV for management of acute hypoxemic respiratory failure, as it may be better tolerated 2
• HFNO is also recommended over conventional oxygen therapy for postextubation acute hypoxemic respiratory failure 2, 3
• HFNO has shown noninferiority to NIV for preventing intubation or death in most types of acute respiratory failure 3

Invasive Mechanical Ventilation

• Consider invasive ventilation when:
  • NIV fails as initial therapy
  • Patient has contraindications to NIV
  • Risk/benefit analysis favors better outcome with invasive ventilation 1
• When using invasive ventilation, set appropriate positive end-expiratory pressure with tidal volumes of 6 mL/kg ideal body weight 2
• Limit peak or plateau pressures to below 30 cmH2O to prevent barotrauma 2
• Prefer spontaneous breathing modes when possible 2

Pharmacological Management

• Administer nebulized bronchodilators during breaks from NIV, or via a nebulizer inserted into the ventilator tubing if the patient is NIV-dependent 2
• Consider heated humidification if the patient reports mucosal dryness or if respiratory secretions are thick 2
• Use sedation cautiously and only with close monitoring; if intubation is not intended should NIV fail, sedation/anxiolysis is indicated for symptom control 2
• For agitated/distressed patients on NIV, consider intravenous morphine 2.5-5 mg (with or without benzodiazepine) to improve tolerance 2

Monitoring and Follow-up

• Regularly assess respiratory rate, heart rate, blood pressure, level of consciousness, and patient comfort 1
• Monitor for treatment failure indicators: deteriorating condition, worsening blood gases, development of new symptoms or complications, intolerance of ventilatory support 2
• Check for common complications: pneumothorax, aspiration pneumonia, mask-related pressure sores, gastric distention 2, 4
• Perform spirometric testing and arterial blood gas analysis while breathing air before discharge for all patients treated with NIV for acute hypercapnic respiratory failure 2
• Refer patients with spinal cord lesions, neuromuscular disease, chest wall deformity, or morbid obesity who develop acute hypercapnic respiratory failure to centers providing long-term ventilation at home 2

Organizational Aspects

• Designate a specific area with trained staff for NIV delivery, with clear protocols for initiation and supervision 2
• Patients with more severe acidosis (pH <7.30) should be managed in a higher dependency area such as HDU or ICU 2
• Patients with respiratory failure from causes where NIV efficacy is not well established (pneumonia, ARDS, asthma) should only receive NIV in HDU or ICU settings with immediate intubation capability 2
• Ensure proper infection control: reprocess reusable masks and exhalation valves, use bacterial filters, and clean ventilator surfaces between patients 2