What is the management approach for a patient with chronic obstructive pulmonary disease (COPD) who has contracted influenza?

Management of COPD with Influenza

Immediately initiate oseltamivir 75 mg orally twice daily for 5 days (if within 48 hours of symptom onset), prednisone 40 mg daily for 5 days, short-acting bronchodilators, and co-amoxiclav for bacterial coverage in hospitalized COPD patients with influenza. 1, 2

Antiviral Therapy

• Start oseltamivir immediately if the patient presents within 48 hours of symptom onset with fever and acute influenza-like illness. 1, 2
• The standard adult dose is 75 mg orally twice daily for 5 days. 1, 2
• Reduce the dose to 75 mg once daily if creatinine clearance is less than 30 mL/minute. 1
• Oseltamivir reduces illness duration by approximately 24 hours and may reduce hospitalization rates. 1, 2
• Evidence from a 2020 randomized controlled trial showed oseltamivir led to significantly better clinical improvement in influenza-like symptoms compared to zanamivir in COPD patients (97.5% vs 83.8% improvement by day 7, P=0.003). 3

Systemic Corticosteroids

• Administer prednisone 40 mg orally daily for 5 days as the standard regimen. 1, 2
• Systemic corticosteroids improve lung function, oxygenation, shorten recovery time, and reduce hospitalization duration in COPD exacerbations. 1, 2

Bronchodilator Therapy

• Initiate short-acting inhaled β2-agonists with or without short-acting anticholinergics as first-line bronchodilator treatment immediately. 1, 2
• Use nebulizers if the patient is too breathless to use standard inhalers effectively, or use spacer devices with metered-dose inhalers. 2
• Continue or initiate long-acting bronchodilators as soon as possible, ideally before hospital discharge. 1

Antibiotic Coverage

• Co-amoxiclav is first-line antibiotic therapy because it covers common secondary bacterial pathogens including Streptococcus pneumoniae and Haemophilus influenzae. 1, 2
• Indications for antibiotics include increased sputum purulence, increased sputum volume, or increased dyspnea. 2
• Doxycycline is an alternative for patients intolerant of beta-lactams. 1
• Avoid macrolides as first-line therapy due to antimicrobial resistance concerns and inferior coverage of H. influenzae. 1

Oxygen Management

• Assess oxygen saturation immediately and maintain SpO2 ≥92% in most patients. 1, 2
• For COPD patients with known CO2 retention, target SpO2 ≥90% and start with controlled oxygen titrated based on repeated arterial blood gas measurements. 1, 2
• High concentrations of oxygen can safely be given in uncomplicated pneumonia without pre-existing COPD. 4
• Obtain arterial blood gases if SpO2 <92% or if the patient has features of severe illness. 2

Severity Assessment and Monitoring

• Calculate CURB-65 score to determine pneumonia severity and guide disposition decisions. 1, 2
• Check vital signs at least twice daily, including temperature, respiratory rate, pulse, blood pressure, mental status, oxygen saturation, and inspired oxygen concentration. 4, 1, 2
• Use an Early Warning Score system for convenient tracking. 4, 2
• Send to the emergency room immediately if respiratory rate >30/min, blood pressure <90/60 mmHg, shortness of breath at rest, confusion, hemoptysis, or bilateral chest signs suggesting pneumonia. 2

Non-Invasive Ventilation

• Consider non-invasive ventilation (NIV) in COPD patients with acute hypercapnic respiratory failure. 2
• Oxygen therapy in patients with pre-existing COPD complicated by ventilatory failure should be guided by repeated arterial blood gas measurements, and NIV may be helpful. 4
• NIV may serve as a bridge to invasive ventilation in patients without pre-existing COPD who develop respiratory failure when level 3 beds are in high demand. 4, 2

ICU/HDU Transfer Criteria

• Transfer to intensive care if failing to maintain SpO2 >92% despite FiO2 >60%, severe respiratory distress, or hemodynamic instability. 1

Microbiological Testing

Early in a Pandemic (Alert Levels 1-3)

• Obtain nose and throat swabs in virus transport medium for all patients. 4
• For patients with influenza-related pneumonia: blood culture (preferably before antibiotics), pneumococcal urine antigen, legionella urine antigen, and sputum gram stain/culture if able to expectorate purulent samples without prior antibiotic treatment. 4

Once Pandemic is Established (Alert Level 4)

• No routine virology testing is recommended. 4
• For non-severe pneumonia (CURB-65 score 0-2), no routine testing is needed. 4
• In patients who do not respond to empirical antibiotic therapy, send sputum samples for gram stain, culture, and antimicrobial susceptibility tests. 4

Discharge Criteria and Follow-Up

• Review patients 24 hours prior to discharge and ensure stability criteria are met: temperature ≤37.8°C, heart rate ≤100/min, respiratory rate ≤24/min, systolic blood pressure ≥90 mmHg, and oxygen saturation ≥90%. 4, 2
• Patients with two or more unstable clinical factors should remain in hospital. 4
• Arrange follow-up for all patients who suffered significant complications or worsening of underlying disease. 2

Prevention for Future Exacerbations

• Ensure the patient receives annual influenza vaccination to prevent future exacerbations. 1, 2
• Influenza vaccination reduces exacerbations and hospitalizations, especially in patients with FEV1 <50% predicted. 5
• Consider pneumococcal vaccination as part of overall COPD management. 1, 2

Common Pitfalls

• Do not delay oseltamivir beyond 48 hours of symptom onset, as efficacy diminishes significantly after this window. 1, 2
• Avoid giving high-flow oxygen without arterial blood gas monitoring in COPD patients with potential CO2 retention, as this can precipitate hypercapnic respiratory failure. 4, 1
• Do not use macrolides as first-line antibiotics due to resistance patterns and poor H. influenzae coverage. 1