What review of systems and initial workup are recommended for a patient presenting with dyspnea?

Review of Systems and Initial Workup for Dyspnea

Immediate Clinical Assessment and Vital Signs

Begin by measuring respiratory rate, blood pressure, heart rate, oxygen saturation, and temperature within minutes of patient contact, as these vital signs determine the urgency of intervention and guide initial treatment decisions. 1, 2

• Respiratory assessment: Document respiratory rate (tachypnea >20 breaths/minute suggests respiratory distress), assess ability to lie flat (orthopnea is highly specific for heart failure), evaluate effort of breathing, and measure oxygen saturation (SpO2 <90% requires supplemental oxygen) 1, 2
• Hemodynamic status: Record systolic and diastolic blood pressure immediately, as systolic BP >140 mmHg with congestion indicates vasodilator therapy while lower pressures may require different management 1, 3
• Cardiac rhythm: Assess heart rate and rhythm, obtain continuous ECG monitoring 1
• Perfusion markers: Check for cool extremities, narrow pulse pressure, and altered mental status as signs of hypoperfusion 1

Critical Historical Elements

Determine whether dyspnea is acute (<4 weeks) or chronic (>4-8 weeks), as this fundamentally changes the differential diagnosis and diagnostic approach. 2, 4

Timing and Onset Pattern

• Sudden onset (minutes to hours) suggests pulmonary embolism, pneumothorax, acute coronary syndrome, or acute heart failure 2
• Gradual progression (weeks to months) indicates heart failure, COPD, interstitial lung disease, or anemia 2, 4

Cardiac-Specific Symptoms

• Orthopnea (dyspnea when lying flat) and paroxysmal nocturnal dyspnea (waking from sleep gasping for air) are highly specific for heart failure 2, 3
• Chest pain or pressure suggests acute coronary syndrome or myocardial ischemia 5, 6
• Palpitations may indicate arrhythmia as the cause 5

Pulmonary-Specific Symptoms

• Cough (productive vs. nonproductive), sputum characteristics, and hemoptysis 4, 6
• Wheezing suggests obstructive airway disease 5, 4
• Fever and sore throat point toward infectious causes 6

Exposure and Risk Factors

• Smoking history and pack-years for COPD and lung cancer risk 5, 4
• Occupational exposures to asbestos, silica, or other inhaled toxins for interstitial lung disease 5
• Recent immobilization, surgery, or travel for pulmonary embolism risk 4
• Medication history, particularly beta-blockers (which can mask cardiac limitation) 5

Physical Examination Findings

Respiratory Examination

• Auscultation: Rales/crackles suggest pulmonary edema or pneumonia; wheezing or prolonged expiratory phase indicates airway obstruction; absent breath sounds suggest pneumothorax or pleural effusion 1, 5, 4
• Percussion: Dullness indicates pleural effusion or consolidation 6
• Inspection: Use of accessory muscles, pursed-lip breathing, or barrel chest deformity 6

Cardiac Examination

• Jugular venous distention indicates elevated right atrial pressure from heart failure or pulmonary hypertension 1, 2, 4
• Cardiac auscultation for murmurs (valvular disease), gallops (S3 suggests heart failure), or irregular rhythm 4, 6

Peripheral Examination

• Peripheral edema suggests volume overload from heart failure or cor pulmonale 1, 3
• Clubbing indicates chronic hypoxemia from interstitial lung disease, cyanotic heart disease, or lung cancer 4
• Cyanosis of lips or nail beds indicates severe hypoxemia 6

First-Line Diagnostic Testing

The American Heart Association recommends proceeding immediately to first-line testing including laboratory tests, chest radiography, electrocardiography, and pulse oximetry, performed concomitantly with clinical assessment. 2, 3

Laboratory Tests

• Complete blood count to identify anemia (a common cause of dyspnea) 2, 4
• Basic metabolic panel to assess for metabolic acidosis and renal function 2, 4
• BNP or NT-proBNP: BNP <100 pg/mL has 96-99% sensitivity for ruling out heart failure; BNP ≥100 pg/mL warrants echocardiography 2, 5
• D-dimer if pulmonary embolism is suspected (though this is more relevant in acute presentations) 4

Imaging

• Chest radiograph to identify pneumonia, pulmonary edema, pleural effusion, pneumothorax, or masses, though it may be normal in nearly 20% of acute heart failure cases 1, 2, 3, 4
• Bedside thoracic ultrasound (if expertise available) for B-lines indicating pulmonary edema and inferior vena cava assessment for volume status 1, 3

Cardiac Testing

• 12-lead ECG is rarely normal in acute heart failure and is necessary to exclude ST-elevation MI, though it is rarely diagnostic by itself 1, 3, 4

Pulmonary Testing

• Pulse oximetry to quantify hypoxemia 1, 2
• Spirometry to identify obstructive (asthma, COPD) or restrictive patterns 2, 4

Second-Line Testing When Initial Workup Is Nondiagnostic

Cardiac Evaluation

• Echocardiography to assess left ventricular ejection fraction, diastolic dysfunction, valvular disease, right ventricular function, and pulmonary hypertension 2, 5, 3
• Immediate echocardiography is not needed during initial evaluation unless hemodynamic instability is present, but should be performed after stabilization, especially in de novo disease 1, 3

Pulmonary Evaluation

• Pulmonary function tests with diffusing capacity (DLCO) when chest radiograph is abnormal or clinical features suggest pulmonary disease 5, 4
• CT chest is the most appropriate imaging study for diagnosing interstitial lung disease, pulmonary vascular abnormalities, or subtle parenchymal disease not visible on chest X-ray 5, 4

Definitive Testing for Unexplained Dyspnea

• Cardiopulmonary exercise testing (CPET) is the definitive test when initial evaluations are nondiagnostic, as it categorizes abnormalities into oxygen delivery (cardiac), oxygen utilization (peripheral muscle/deconditioning), or ventilatory disorders (pulmonary) 2, 5
• CPET can identify exercise-induced bronchoconstriction, deconditioning, early cardiovascular disease, and pulmonary vascular disease that are not apparent on resting tests 5

Common Pitfalls to Avoid

• Do not assume clinical assessment alone is sufficient: Clinical evaluation has high specificity (96%) but low sensitivity (59%) for cardiac causes, making objective testing mandatory 2, 5
• Do not be falsely reassured by normal chest radiography: Early heart failure and diastolic dysfunction may have normal chest X-rays 2, 3
• Do not assume a negative cardiac stress test excludes all cardiac causes: It primarily rules out obstructive coronary disease but not heart failure with preserved ejection fraction (HFpEF), valvular disease, or pulmonary hypertension 5
• Consider multifactorial causes: More than 30% of chronic dyspnea cases have multiple contributing etiologies, most commonly cardiac and pulmonary 2, 3, 4
• Do not delay treatment while awaiting complete diagnostic workup in acute presentations: Initiate treatment based on blood pressure and congestion patterns using vasodilators and/or diuretics concurrently with diagnostic evaluation 1, 3