What is the management of Type 2 respiratory failure?

Management of Type 2 Respiratory Failure

The management of type 2 respiratory failure should begin with controlled oxygen therapy targeting a saturation of 88-92% in all patients, followed by non-invasive ventilation (NIV) when pH <7.35 and PaCO2 >6.5 kPa persist despite optimal medical therapy. 1

Initial Assessment and Management

• Perform arterial blood gas (ABG) analysis to confirm type 2 respiratory failure (hypoxemia with hypercapnia: PaO2 <60 mmHg, PaCO2 >45 mmHg) 2
• Obtain chest radiography to identify potential causes or complications, but do not delay treatment in severe acidosis 1
• Position the patient in semi-recumbent position (30-45° head elevation) if hemodynamically stable 2
• Document an individualized treatment plan at the start, including measures to be taken if initial therapy fails 1

Oxygen Therapy

• Administer controlled oxygen therapy targeting saturation of 88-92% to prevent worsening hypercapnia 1
• Use appropriate delivery devices (Venturi masks or nasal cannulae) with oxygen entrained as close to the patient as possible 1
• Continuously monitor oxygen saturation for at least 24 hours after commencing treatment 2
• Recheck arterial blood gases 1-2 hours after starting oxygen therapy to ensure adequate oxygenation without worsening respiratory acidosis 2

Non-Invasive Ventilation (NIV)

• Initiate NIV when pH <7.35 and PaCO2 >6.5 kPa persist or develop after one hour of optimal medical therapy 1
• For patients with PaCO2 between 6.0 and 6.5 kPa, NIV should be considered on a case-by-case basis 1
• Severe acidosis alone does not preclude a trial of NIV in an appropriate setting with ready access to staff who can perform safe endotracheal intubation 1
• Start with low pressures (e.g., IPAP 10-12 cmH2O, EPAP 4-5 cmH2O) and gradually increase as tolerated 3
• Maximize time on NIV in the first 24 hours depending on patient tolerance and complications 1
• Monitor for improvement in physiological parameters, particularly pH and respiratory rate, within 1-2 hours of starting NIV 1
• Consider using Average Volume-Assured Pressure Support (AVAPS) mode, which may provide more rapid improvement in pH and PaCO2 compared to standard BiPAP modes 4
• If sleep-disordered breathing pre-dates or complicates the episode, use a controlled mode of NIV overnight 1

Pharmacological Management

• Administer nebulized bronchodilators (β-agonists and/or anticholinergics) during breaks from NIV 3
• Consider systemic corticosteroids for patients with COPD exacerbation 3
• Budesonide combined with NIV may improve outcomes in AECOPD patients with type 2 respiratory failure by decreasing serum inflammatory markers and improving lung compliance 5
• Prescribe antibiotics for patients with increased sputum purulence or requiring mechanical ventilation 2
• Treat reversible causes of respiratory failure appropriately 1

Invasive Mechanical Ventilation

• Consider invasive mechanical ventilation when NIV fails (no improvement in pH and PaCO2 after 4-6 hours) 1
• Intubation is indicated when risk/benefit analysis favors a better outcome with invasive mechanical ventilation than with NIV 1
• Set adequate positive end-expiratory pressure with tidal volumes of 6 mL/kg ideal body weight 3
• Limit peak or plateau pressures to below 30 cmH2O to prevent barotrauma 3

Monitoring and Treatment Adjustment

• Measure arterial blood gases after 1-2 hours of NIV and again after 4-6 hours if the earlier sample showed little improvement 3
• Worsening physiological parameters, particularly pH and respiratory rate, indicate the need to change management strategy (clinical review, change of interface, adjustment of ventilator settings, considering endotracheal intubation) 1
• NIV can be discontinued when there has been normalization of pH and PaCO2 and general improvement in the patient's condition 1
• Taper NIV use during the day in the following 2-3 days, depending on PaCO2 while self-ventilating, before discontinuing overnight 1

Long-term Considerations

• Discuss management of possible future episodes of acute hypercapnic respiratory failure with patients following an episode requiring ventilatory support, as there is a high risk of recurrence 1
• Be aware that the 2-year and 5-year mortality rates for COPD patients surviving their first episode of respiratory failure requiring NIV are high (48% and 74% respectively) 6
• Advanced age, low BMI, and prior domiciliary oxygen use are associated with higher mortality at 5 years 6
• All patients treated with NIV for acute hypercapnic respiratory failure should undergo spirometric testing and arterial blood gas analysis while breathing air before discharge 3

Common Pitfalls and Caveats

• Avoid excessive oxygen administration, which can worsen hypercapnia in susceptible patients 1, 7
• Do not delay NIV initiation when indicated, as earlier intervention leads to better outcomes 1
• NIV should not delay escalation to invasive mechanical ventilation when this is more appropriate 1
• Recognize that clinicians often underestimate survival in AECOPD treated by invasive mechanical ventilation 1
• Patients with more severe acidosis (pH <7.30) should be managed in a higher dependency area such as HDU or ICU 3