What is the immediate management for a patient with chronic obstructive pulmonary disease (COPD) experiencing an exacerbation?

Immediate Management of COPD Exacerbation

For patients experiencing a COPD exacerbation, immediately initiate controlled oxygen therapy targeting 88-92% saturation, increase or add inhaled bronchodilators (beta-agonists and/or anticholinergics), start antibiotics if two or more cardinal symptoms are present (increased dyspnea, sputum volume, or purulent sputum), and administer systemic corticosteroids 30 mg daily for severe cases. 1, 2

Initial Assessment and Oxygen Therapy

Oxygen Administration

• Start with controlled oxygen immediately using a 24% Venturi mask at 2-3 L/min, nasal cannulae at 1-2 L/min, or 28% Venturi mask at 4 L/min, targeting oxygen saturation of 88-92%. 1
• If saturation remains below 88% despite 28% Venturi mask in prehospital care, switch to nasal cannulae at 2-6 L/min or simple face mask at 5 L/min. 1
• For patients with respiratory rate >30 breaths/min, increase the flow rate into Venturi masks above the minimum specified to compensate for increased inspiratory flow (note: this does not increase oxygen concentration delivered). 1
• Obtain arterial blood gases within 30-60 minutes of starting oxygen to check for hypercapnia (PCO2 >6 kPa) and acidosis (pH <7.35). 1, 2

Critical Pitfall in Oxygen Therapy

Avoid excessive oxygen administration—if PaO2 rises above 10.0 kPa due to overoxygenation, the risk of respiratory acidosis increases significantly in patients with hypercapnic respiratory failure. 1

Pharmacological Management

Bronchodilators (First-Line)

• Immediately add or increase beta-agonists and/or anticholinergic drugs via inhaled route. 1
• Verify the patient can use their inhaler device effectively; nebulizers are usually not required in mild-moderate exacerbations. 1
• Short-acting bronchodilators provide immediate symptom relief and should be used as rescue therapy. 2

Antibiotics (When Indicated)

• Administer antibiotics if two or more of the following cardinal symptoms are present: increased breathlessness, increased sputum volume, or development of purulent sputum. 1
• Antibiotic therapy reduces short-term mortality by 77%, treatment failure by 53%, and sputum purulence by 44%. 2
• Choose based on local resistance patterns; typical empirical treatment includes aminopenicillin with clavulanic acid, a macrolide, or tetracycline for 5-7 days. 2
• Do not delay antibiotics in patients requiring mechanical ventilation, as this increases mortality and risk of secondary nosocomial pneumonia. 2

Systemic Corticosteroids

• Administer oral corticosteroids 30 mg daily for one week in severe exacerbations or if airflow obstruction fails to respond to increased bronchodilator dose. 1, 2
• In community settings, use corticosteroids if: patient already on oral corticosteroids, previously documented response to corticosteroids, inadequate response to bronchodilators, or first presentation of airflow obstruction. 1
• Do not continue long-term after the acute episode. 1

Severity Assessment and Triage

High-Priority Indicators Requiring Hospital Admission

• Patients with respiratory rate >30 breaths/min should be triaged as very urgent with blood gases measured on arrival. 1
• Significant likelihood of severe COPD or hypercapnic respiratory failure requires immediate hospital evaluation. 1
• Loss of alertness, confusion, or cyanosis indicates severe deterioration. 1
• Peripheral edema, audible wheeze, tachypnea, and use of accessory muscles suggest significant deterioration. 1

Blood Gas Interpretation Algorithm

• If pH ≥7.35 and PCO2 normal after initial oxygen: Target saturation 94-98% unless history of previous hypercapnic respiratory failure (then maintain 88-92%). Recheck gases at 30-60 minutes. 1
• If PCO2 elevated but pH ≥7.35: Patient likely has chronic hypercapnia; maintain 88-92% target and recheck gases at 30-60 minutes. 1
• **If PCO2 >6 kPa (45 mmHg) AND pH <7.35:** Start non-invasive ventilation (NIV) with targeted oxygen if respiratory acidosis persists >30 minutes after standard medical management. 1, 2

Non-Invasive Ventilation

NIV is the preferred initial mode of ventilation for acute respiratory failure in COPD exacerbations, reducing mortality and intubation rates with 80-85% success rate. 2

• Initiate NIV for hypercapnic respiratory failure with acidosis (pH <7.35) that persists despite optimal medical therapy. 1, 2
• Critical caveat: Patients who fail NIV and require invasive ventilation as rescue therapy experience greater morbidity, longer hospital stays, and higher mortality than those initially intubated. 2

Hospital Admission Workup

Immediate Investigations

• Arterial blood gases noting inspired oxygen concentration (FiO2). 1, 2
• Chest radiograph to exclude pneumonia, pneumothorax, pulmonary edema, or lung cancer. 1
• Full blood count within first 24 hours. 1
• Spirometry should be measured at least once during admission to confirm airflow obstruction and assess FEV1 as indicator of disease severity. 1

Monitoring Requirements

• Recheck blood gases after 30-60 minutes or with any clinical deterioration, even if initial PCO2 was normal, as hypercapnic respiratory failure can develop during admission. 1
• Monitor for rising PCO2 or falling pH indicating worsening respiratory acidosis. 1

Differential Diagnoses to Exclude

Consider and rule out these alternative or concurrent diagnoses in every COPD exacerbation: 1

• Pneumonia
• Pneumothorax
• Left ventricular failure/pulmonary edema
• Pulmonary embolus
• Lung cancer
• Upper airway obstruction