What is the initial management for a patient with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and type 2 respiratory failure?

Management of AECOPD with Type 2 Respiratory Failure

Begin immediately with controlled oxygen therapy targeting saturations of 88-92% using a 24% Venturi mask at 2-3 L/min or 28% Venturi mask at 4 L/min, obtain arterial blood gases within minutes of arrival, and initiate non-invasive ventilation (NIV) when pH<7.35 and pCO2 >6.5 kPa persist despite optimal medical therapy. 1

Immediate Oxygen Management

Controlled oxygen is critical—uncontrolled high-flow oxygen increases mortality by worsening acidosis and hypercapnia. 1

• Target oxygen saturation of 88-92% in all patients with AECOPD and type 2 respiratory failure 1, 2
• Use 24% Venturi mask at 2-3 L/min, nasal cannulae at 1-2 L/min, or 28% Venturi mask at 4 L/min 3
• Pre-hospital titrated oxygen reduces mortality by 58% for all patients and 78% for confirmed COPD compared to high-concentration oxygen 1
• Both hypoxemia (PaO2<60 mmHg) and hyperoxemia (PaO2>100 mmHg) significantly increase risk of serious adverse outcomes including death 4

Arterial Blood Gas Assessment

• Obtain ABG immediately on arrival before any intervention 1, 3
• Repeat ABG 30-60 minutes after initiating oxygen therapy to assess for CO2 retention 1, 3
• Recheck ABG after 30-60 minutes or with any clinical deterioration, even if initial pCO2 was normal 3
• Do not delay chest X-ray if pH<7.25 (severe acidosis)—initiate NIV first 1

Pharmacological Therapy

Bronchodilators

• Administer salbutamol 2.5-5 mg nebulized with or without ipratropium bromide 0.25-0.5 mg immediately 3, 5
• Combined therapy produces additional improvement in FEV1 and extends duration of benefit to 5-7 hours versus 3-4 hours with beta-agonist alone 6

Systemic Corticosteroids

• Give prednisone 30-40 mg orally daily for 5 days if patient can tolerate oral medications 3
• Alternatively, use intravenous corticosteroids for severe exacerbations 2, 5
• Improves lung function, oxygenation, and shortens recovery time 3, 5

Antibiotics

• Prescribe antibiotics when patient has increased dyspnea, increased sputum volume, AND increased sputum purulence 3, 2
• Also indicated if two cardinal symptoms present with one being increased sputum purulence, or if mechanical ventilation required 3
• First-line options: amoxicillin/clavulanic acid, tetracycline derivatives, or macrolides for 5-7 days 3, 2
• Never withhold antibiotics in ventilated patients—delays increase mortality and secondary nosocomial pneumonia 2, 5

Non-Invasive Ventilation (NIV) Initiation

NIV is the first-line ventilatory support and reduces mortality, intubation rates, complications, and length of stay. 1, 2

Indications for NIV

• Start NIV when pH<7.35 and pCO2 >6.5 kPa persist or develop despite optimal medical therapy (Grade A evidence) 1, 5
• Success rate of 80-85% when appropriately applied 2, 5

NIV Settings

• Use CPAP 4-8 cmH2O plus pressure support ventilation 10-15 cmH2O 5
• AVAPS mode may provide more rapid improvement in pH and pCO2 compared to BiPAP S/T mode 7

Location and Monitoring

• Severe acidosis (pH<7.25) does not preclude NIV trial but requires appropriate area with ready access to intubation capability 1
• Document individualized patient plan at treatment start regarding measures if NIV fails 1
• Monitor pH and respiratory rate closely—worsening indicates need to adjust settings, change interface, or proceed to intubation 1

Criteria for Invasive Mechanical Ventilation

Do not delay escalation to invasive ventilation when appropriate—NIV failure requiring rescue intubation has worse outcomes than initial intubation. 2, 5

Absolute Indications for Immediate Intubation

• Severe acidosis (pH<7.25) with hypercapnia (pCO2 >60 mmHg) 5
• Life-threatening hypoxemia (PaO2/FiO2 <200 mmHg) 5
• Tachypnea >35 breaths/min 5
• Impaired mental status, somnolence, inability to cooperate 5
• Copious/viscous secretions with high aspiration risk 5
• Recent facial or gastroesophageal surgery, craniofacial trauma 5

NIV Failure Indicators

• Worsening pH and respiratory rate despite NIV 1
• Clinical deterioration with altered consciousness 1
• Inability to clear secretions 1

Common Pitfalls to Avoid

• Never use uncontrolled high-flow oxygen—this is the most common error and directly increases mortality 1, 4
• Avoid methylxanthines due to increased side effects without proven benefit 5
• Do not continue NIV when patient is deteriorating rather than escalating to invasive ventilation—this increases mortality 1
• Ensure frequent reassessment for complications including pneumothorax, which usually requires chest tube and NIV review 1
• Avoid overtightening masks to prevent pressure injuries 1
• In agitated/distressed patients on NIV, consider intravenous morphine 2.5-5 mg (±benzodiazepine) for symptom relief and improved NIV tolerance, but only with close monitoring 1

Secretion Management

• Use mechanical insufflation-exsufflation with standard physiotherapy when cough is ineffective and sputum retention present 1
• Consider mini-tracheostomy for aiding secretion clearance in cases of weak cough or excessive secretions 1