Pulmonary System Examination, Evaluation, and Clinical Decision-Making
Pulmonary evaluation
Begin with the symptom pattern: dyspnea at rest or exertion, cough, sputum, hemoptysis, wheeze, and pleuritic pain. Ask about exposures, smoking, inhalers, and prior spirometry. Observe work of breathing-accessory muscle use, tripod position, pursed-lip breathing, nasal flaring, and ability to speak in sentences. Cyanosis is a late and unreliable sign.
Percussion and auscultation refine the hypothesis. Dullness with decreased breath sounds and crackles suggests effusion or consolidation; hyperresonance with absent breath sounds suggests pneumothorax. Crackles are nonspecific, and wheezing can reflect asthma, COPD, heart failure, or upper airway obstruction. Tactile fremitus increases with consolidation and decreases with effusion or pneumothorax.
Objective data include pulse oximetry, ABG, spirometry, lung volumes, diffusion capacity, and imaging. Spirometry distinguishes obstruction (reduced FEV1/FVC) from restriction (reduced FVC with preserved ratio), but a normal ratio does not exclude disease. A normal SpO2 does not exclude pulmonary embolism or early pneumonia.
Clinical decision-making
Sudden unilateral pleuritic pain, tachycardia, and absent breath sounds on one side point to pneumothorax until imaging proves otherwise. Fever, focal crackles, and dullness suggest pneumonia. Chronic productive cough with persistent obstruction suggests COPD; episodic reversible symptoms suggest asthma.
Worked example. A 24-year-old tall man develops sudden right-sided pain and dyspnea after lifting. He is tachycardic, the right hemithorax is hyperresonant, and breath sounds are absent. This is pneumothorax, not a pulled muscle; he needs urgent evaluation. Rule of thumb: assess work of breathing before trusting a single oxygen saturation value.