COPD in Critically Ill Patients

Background

• Acute exacerbations of chronic obstructive pulmonary disease (COPD) are characterized by increased dyspnea and/or cough and sputum production that worsens in < 14 days, may be accompanied by tachypnea or tachycardia, and is often associated with increased inflammation due to infection, pollution, or other airway insult.
• Patients hospitalized for COPD exacerbations may require mechanical ventilation.
• Mechanical ventilation can be delivered noninvasively, using either a nasal or facial mask, or invasively, via an endotracheal tube or tracheostomy.

Evaluation

• Assess patients with acute COPD exacerbations for signs of respiratory failure:
  • severe dyspnea with signs suggestive of respiratory muscle fatigue and/or increased work of breathing, such as
    • use of respiratory accessory muscles
    • paradoxical abdominal motion
    • retraction of intercostal spaces
  • respiratory acidosis (pH ≤ 7.35) with partial pressure of arterial carbon dioxide (PaCO₂) ≥ 6 kilopascal [kPa] or ≥ 45 mm Hg)
  • persistent hypoxemia despite supplemental oxygen therapy

Management

• Use noninvasive ventilation (NIV) in patients with acute COPD exacerbations with acute respiratory failure who do not require emergent intubation (Strong recommendation).
  • Use of noninvasive positive pressure ventilation (NPPV) for the treatment of acute COPD exacerbations reduces mortality and the need for intubation.
  • Relative contraindications include respiratory arrest, cardiovascular instability, copious secretions, high aspiration risk, inability to assess mental status due to hypercapnia, extreme obesity, thermal upper airway injury, and inability to properly fit a mask.
• Intubation may be indicated for patients who cannot tolerate or fail NIV or in whom NIV is contraindicated, as well as for other indications for mechanical ventilation.
  • The decision to intubate should take into account the likelihood of reversing the precipitating event and patient preferences.
  • Ventilation strategies for mechanically ventilated patients focus on the correction of respiratory acidosis and hypoxemia while avoiding hyperinflation.
    • Management goals include using low tidal volumes (5-7 mL/kg), shortening inspiratory time, and providing adequate sedation for controlling respiratory rate.
    • Conservative oxygenation using lower SpO₂ targets (94%-98% or 88%-92%) may be associated with lower or similar mortality compared to higher SpO₂ targets (97%-100% or 96%) in critically ill mechanically ventilated patients.
• Medications are similar to noncritically ill patients:
  • use short-acting bronchodilators (such as albuterol) with or without a short-acting muscarinic antagonist (such as ipratropium) as the initial bronchodilator therapy, with 1-2 puffs/hour via metered-dose inhaler (instead of continuous nebulization) for 2-3 doses and then every 2-4 hours as needed
  • use systemic corticosteroids such as prednisolone 40 mg/day orally or IV equivalent for 5 days (Strong recommendation)
  • consider antibiotics for 5 days if (Weak recommendation)
    • increased sputum purulence and ≥ 1 of increased sputum volume and/or increased dyspnea
    • requirement for noninvasive or invasive mechanical ventilation