What is the most likely diagnosis and acute management for a patient presenting with clear sputum, progressive shortness of breath, and hyper‑resonant chest percussion?

Most Likely Diagnosis: COPD Exacerbation

The clinical presentation of clear mucous sputum, progressive dyspnea, and hyperresonant chest percussion strongly suggests an acute exacerbation of chronic obstructive pulmonary disease (COPD), likely in a patient with underlying emphysema. 1

Key Diagnostic Features

The triad of findings points specifically to COPD exacerbation:

• Hyperresonance on percussion indicates air trapping and overinflation characteristic of emphysema, distinguishing this from pneumonia, heart failure, or asthma 1
• Progressive dyspnea represents worsening airflow obstruction, a cardinal feature of COPD exacerbation 1
• Clear (non-purulent) sputum suggests a viral trigger or non-bacterial cause, though this does not exclude COPD exacerbation 1

Critical Differential Diagnoses to Exclude

Before confirming COPD exacerbation, immediately rule out these life-threatening conditions:

• Pneumothorax (sudden onset, unilateral hyperresonance, absent breath sounds) 1
• Pneumonia (fever >38°C, heart rate >100, respiratory rate >24, focal consolidation on exam) 1
• Pulmonary embolism (sudden onset, pleuritic chest pain, hemoptysis) 1
• Left ventricular failure/pulmonary edema (orthopnea, crackles, elevated JVP) 1

Acute Management Algorithm

Immediate First-Line Treatment

1. Bronchodilators (Start Immediately)

• Administer short-acting β2-agonist (albuterol) combined with short-acting anticholinergic (ipratropium) via nebulizer or metered-dose inhaler with spacer 2, 3, 4
• Give every 4-6 hours during acute phase; combination therapy provides superior bronchodilation compared to either agent alone 2
• Do NOT use theophylline due to increased side effects without added benefit 2, 5

2. Systemic Corticosteroids

• Oral prednisone 30-40 mg daily for 5 days is the gold standard 2, 4
• Oral administration is equally effective to IV methylprednisolone but with fewer adverse effects and lower costs 2
• Never extend beyond 5-7 days as this increases adverse effects without additional clinical benefit 2
• Benefits begin at 6-12 hours, so start early 2

3. Oxygen Therapy

• Target oxygen saturation 88-92% to avoid CO2 retention 2, 4
• Controlled oxygen delivery is critical in COPD patients 4

Antibiotic Decision-Making

Prescribe antibiotics ONLY if the patient has increased sputum purulence PLUS either increased dyspnea OR increased sputum volume 1, 2, 3

In this case with clear (non-purulent) sputum, antibiotics are NOT indicated unless two of the three Anthonisen criteria are met 1, 3. The clear sputum argues against bacterial superinfection 1.

Critical Pitfall: Diuretic Misuse

Do NOT use furosemide (Lasix) unless there is documented concurrent left ventricular failure or pulmonary edema 2. The hyperresonance and clear sputum make heart failure unlikely. Only use diuretics if:

• Peripheral edema is present as a complication 2
• Clear evidence of left ventricular failure on examination or chest radiograph 2

When to Escalate Care

Consider hospitalization if: 4

• Severe dyspnea not responding to initial bronchodilator treatment
• Confusion or lethargy
• Respiratory failure (oxygen saturation <88% despite supplemental oxygen)
• Inability to manage at home

For acute hypercapnic respiratory failure, initiate noninvasive ventilation (NIV) immediately as first-line therapy 2.

Post-Acute Management

• Schedule follow-up within 1-2 weeks after the exacerbation 4
• Initiate or optimize maintenance therapy with long-acting bronchodilators (LAMA, LABA, or LAMA/LABA/ICS triple therapy) before discharge 2, 4
• Refer to pulmonary rehabilitation within 3 weeks to reduce hospital readmissions 2
• Address smoking cessation if applicable, as this is the single most critical intervention 3

Important Nuance

While blood eosinophil count ≥2% predicts better corticosteroid response, current guidelines recommend treating all COPD exacerbations requiring emergent care regardless of eosinophil levels 2. The clear sputum does not exclude COPD exacerbation, as viral infections account for approximately one-third of episodes 1.