What is the recommended management for an acute COPD exacerbation, including oxygen targets, bronchodilator regimen, systemic corticosteroid dosing, antibiotic choice, ventilation criteria, and discharge planning?

Management of Acute COPD Exacerbation

For an acute COPD exacerbation, immediately initiate combined short-acting β₂-agonist (salbutamol 2.5–5 mg) plus short-acting anticholinergic (ipratropium 0.25–0.5 mg) via nebulizer every 4–6 hours, oral prednisone 30–40 mg daily for exactly 5 days, controlled oxygen targeting SpO₂ 88–92%, and antibiotics for 5–7 days when sputum purulence is present with either increased dyspnea or sputum volume. 1

Immediate Assessment and Oxygen Management

Target oxygen saturation of 88–92% using controlled-delivery devices such as a 24–28% Venturi mask or nasal cannula at 1–2 L/min to correct life-threatening hypoxemia while minimizing CO₂ retention. 1 Higher oxygen concentrations can aggravate hypercapnic respiratory failure and increase mortality in COPD patients. 1

• Obtain an arterial blood gas within 60 minutes of starting oxygen to detect hypercapnia (PaCO₂ > 45 mmHg) or acidosis (pH < 7.35), which signal impending respiratory failure. 1
• Repeat ABG at 30–60 minutes (or sooner if clinical deterioration occurs) to detect rising PaCO₂ or falling pH. 1
• If pH falls below 7.26 with rising PaCO₂, prepare immediately for noninvasive ventilation. 1
• If initial ABG shows normal pH and PaCO₂, the target saturation may be increased to 94–98% unless the patient has prior history of hypercapnic failure requiring NIV or usual stable saturation is < 94%. 1

Bronchodilator Therapy

Administer combined short-acting β₂-agonist (salbutamol 2.5–5 mg) plus short-acting anticholinergic (ipratropium 0.25–0.5 mg) via nebulizer every 4–6 hours during the acute phase. 1 This combination provides superior bronchodilation lasting 4–6 hours compared with either agent alone. 1

• Nebulizers are preferred over metered-dose inhalers in sicker hospitalized patients because they are easier to use and don't require coordination of 20+ inhalations needed to match nebulizer efficacy. 1
• Power nebulizers with compressed air, not oxygen, when PaCO₂ is elevated or respiratory acidosis is present, while providing supplemental oxygen via low-flow nasal cannula (1–2 L/min) concurrently. 1
• Avoid intravenous methylxanthines (theophylline/aminophylline) because they increase adverse effects without added benefit. 1

Systemic Corticosteroid Protocol

Give oral prednisone 30–40 mg once daily for exactly 5 days, started immediately on presentation. 1, 2 This short course is as effective as a 14-day regimen while reducing cumulative steroid exposure by > 50%. 1, 2

• Oral administration is equally effective to intravenous and should be the default route unless the patient cannot tolerate oral intake. 1, 2
• If oral administration is not possible, use IV hydrocortisone 100 mg. 2
• Corticosteroids improve lung function and oxygenation, shorten recovery time and hospital stay, reduce treatment failure by > 50%, and lower the risk of rehospitalization for a subsequent exacerbation within the first 30 days. 1, 2, 3
• Do not extend systemic corticosteroids beyond 5–7 days unless there is a separate indication, as this increases adverse effects without additional benefit. 1, 2
• Blood eosinophil count ≥ 2% predicts better response to corticosteroids, but current guidelines recommend treating all COPD exacerbations requiring emergent care regardless of eosinophil levels. 2

Antibiotic Therapy

Prescribe antibiotics for 5–7 days when sputum purulence is present together with either increased dyspnea or increased sputum volume (two of the three cardinal symptoms). 1 This strategy reduces short-term mortality by approximately 77%, treatment failure by 53%, and sputum purulence by 44%. 1

• First-line agents (chosen according to local resistance patterns) include amoxicillin-clavulanate 875/125 mg orally twice daily, doxycycline 100 mg orally twice daily, or macrolides (azithromycin, clarithromycin). 1
• The most common causative organisms are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. 1, 4
• Antibiotics are also indicated when all three cardinal symptoms are present, and in any patient requiring mechanical ventilation (invasive or noninvasive). 1

Noninvasive Ventilation for Hypercapnic Respiratory Failure

Initiate NIV immediately as first-line therapy when acute hypercapnic respiratory failure (PaCO₂ > 45 mmHg) with acidosis (pH < 7.35) persists for more than 30 minutes after standard medical management. 1

• NIV improves gas exchange, reduces work of breathing, lowers intubation rates by approximately 50%, shortens hospital stay, and improves survival. 1, 5
• Success rates in appropriately selected patients are 80–85%. 1
• Contraindications to NIV include altered mental status with inability to protect the airway, large-volume secretions, hemodynamic instability, or recent facial/upper-airway surgery. 1
• If NIV fails or contraindications exist, prepare for invasive mechanical ventilation. 1

Hospitalization Criteria

Hospital admission or emergency-department evaluation is indicated for any of the following: 1

• Marked increase in dyspnea unresponsive to outpatient therapy
• Respiratory rate > 30 breaths/min
• Inability to eat or sleep because of respiratory symptoms
• New or worsening hypoxemia (SpO₂ < 90% on room air)
• New or worsening hypercapnia (PaCO₂ > 45 mmHg)
• Altered mental status or loss of alertness
• Persistent rhonchi after initial treatment requiring continued nebulization
• High-risk comorbidities (pneumonia, cardiac arrhythmia, heart failure, diabetes)
• Inability to care for oneself at home

Discharge Planning and Follow-Up

Arrange pulmonary rehabilitation to start within three weeks after discharge, as early rehabilitation reduces readmission rates and improves quality of life. 1 Initiating rehabilitation during the hospital stay is associated with increased mortality. 1

• Before discharge, initiate or optimize long-acting bronchodilator therapy (LAMA, LABA, or combinations). 1
• Do not step down from triple therapy (LAMA + LABA + ICS) during or immediately after an exacerbation, as withdrawal of inhaled corticosteroids raises the risk of recurrent exacerbations. 1
• Provide intensive smoking cessation counseling with nicotine replacement therapy and behavioral intervention at every visit for current smokers. 1, 5
• Review inhaler technique to ensure proper use and adherence. 1
• Schedule follow-up within 3–7 days to assess response. 1

Common Pitfalls to Avoid

• Never administer high-flow oxygen (> 28% FiO₂ or > 4 L/min) without arterial blood-gas monitoring, as this can exacerbate hypercapnic respiratory failure and increase mortality. 1
• Never delay NIV in patients with acute hypercapnic respiratory failure meeting criteria (pH < 7.35, PaCO₂ > 45 mmHg). 1
• Never use systemic corticosteroids beyond 5–7 days for a single exacerbation unless there is a separate indication. 1, 2
• Never use theophylline in acute exacerbations due to its side effect profile without added benefit. 1, 6
• Never power nebulizers with oxygen in patients with hypercapnia; use compressed air instead. 1