What is the management approach for a patient with Chronic Obstructive Pulmonary Disease (COPD) experiencing a chest infection?

Management of Chest Infection in COPD

Patients with COPD experiencing a chest infection should receive bronchodilators, antibiotics if they have increased dyspnea, sputum volume, and purulence, and a short course of systemic corticosteroids, with oxygen therapy carefully titrated to maintain adequate oxygenation without causing respiratory acidosis. 1, 2

Initial Assessment

• Evaluate for key symptoms including increased dyspnea, increased sputum volume, increased sputum purulence, increased wheeze, chest tightness, and fluid retention 2
• Consider differential diagnoses including pneumonia, pneumothorax, left ventricular failure, pulmonary embolism, lung cancer, and upper airway obstruction 2
• For patients requiring hospital assessment, obtain arterial blood gases, chest radiograph, full blood count, urea and electrolytes, and ECG 2, 1
• If purulent sputum is present, send for culture, and if pneumonia is suspected, obtain blood cultures 1

Bronchodilator Therapy

• Increase the dosage of existing bronchodilators or add new ones if there is evidence of worsening airflow obstruction 2
• For moderate exacerbations, use a beta-agonist (salbutamol 2.5-5 mg or terbutaline 5-10 mg) or an anticholinergic drug (ipratropium bromide 0.25-0.5 mg) 2
• For severe exacerbations or poor response to single agents, administer both beta-agonists and anticholinergics 2, 1
• The inhaled route is preferable, ensuring the patient can use the device effectively 2

Antibiotic Therapy

• Prescribe antibiotics when patients present with at least two of the following: increased dyspnea, increased sputum volume, and increased sputum purulence 2, 1
• First-line antibiotics include amoxicillin or tetracycline, unless these were used with poor response prior to the current exacerbation 2, 1
• For more severe exacerbations or lack of response to first-line agents, consider broader-spectrum antibiotics 2
• Target common pathogens including Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis 3
• Consider risk factors for Pseudomonas aeruginosa, including previous P. aeruginosa isolation, hospitalization in the past 12 months, and bronchiectasis 4

Corticosteroid Therapy

• For hospitalized patients, administer a 5-7 day course of systemic corticosteroids (prednisolone 30-40 mg/day or 100 mg hydrocortisone if oral route not possible) 2, 1
• In the community setting, use oral corticosteroids only if: 2
  • The patient is already on oral corticosteroids
  • There is a previously documented response to oral corticosteroids
  • The airflow obstruction fails to respond to increased bronchodilator dose
  • This is the first presentation of airflow obstruction

Oxygen Therapy

• For hospitalized patients, the goal is to achieve a PaO2 of at least 6.6 kPa (60 mmHg) without causing respiratory acidosis (pH below 7.26) 2, 1
• In patients over 50 years with COPD, initially limit oxygen to 28% via Venturi mask or 2 L/min via nasal cannulae until arterial blood gases are known 2, 1
• Check arterial blood gases within 60 minutes of starting oxygen therapy and after any change in oxygen concentration 1

Additional Therapies

• If response to standard treatments is poor, consider intravenous methylxanthines (aminophylline 0.5 mg/kg per hour), though evidence for effectiveness is limited 2, 1
• For patients with peripheral edema and raised jugular venous pressure, administer diuretics 2
• Consider non-invasive ventilation for patients with persistent hypercapnic respiratory failure despite maximal medical therapy 2, 1

Hospital Admission Criteria

• Consider hospitalization for patients with: 1
  • Marked increase in symptom intensity
  • Severe underlying COPD
  • New physical signs (e.g., cyanosis, peripheral edema)
  • Failure to respond to initial medical management
  • Significant comorbidities
  • Insufficient home support

Follow-up After Exacerbation

• Review patients who fail to respond fully to treatment, considering chest radiography and specialist referral 2
• Use the follow-up visit to help the patient plan for future exacerbations 2
• Provide advice on smoking cessation, lifestyle modifications, activity levels, and medication review 2

Common Pitfalls and Caveats

• Avoid excessive oxygen administration in COPD patients, as this may worsen hypercapnia and respiratory acidosis 2, 1
• Do not routinely continue oral corticosteroids long-term after an acute exacerbation 2
• Remember that antibiotic overuse contributes to bacterial resistance; use only when indicated by clinical criteria 3, 4
• Consider prophylactic antibiotic therapy only in patients with severe or very severe COPD with frequent exacerbations despite optimal treatment 5