What is the best course of action for a patient with a history of smoking, presenting with dyspnea (difficulty breathing) and a heaviness sensation in the chest, slightly reproducible on palpation, and initial complaint of right flank pain?

Immediate Diagnostic Workup for Chest Discomfort with Dyspnea in a Smoker

Begin with chest radiography immediately, as this is the most appropriate initial imaging study for dyspnea of unclear etiology and can reveal a wide variety of abnormalities including pulmonary, cardiac, pleural, and chest wall pathology. 1

Initial Clinical Assessment

Measure vital signs and quantify dyspnea severity objectively:

• Record respiratory rate, oxygen saturation via pulse oximetry, blood pressure, heart rate, and temperature 2
• Assess effort of breathing, ability to tolerate supine position, and degree of hypoxia 2
• Evaluate for signs of hypoperfusion: cool extremities, altered mental status, narrow pulse pressure 2
• Initiate continuous monitoring with pulse oximetry, blood pressure, respiratory rate, and ECG 2

Examine specifically for:

• Reproducible chest wall tenderness - The fact that discomfort is "slightly reproducible when palpated" suggests possible musculoskeletal etiology, but this does NOT exclude serious cardiopulmonary pathology 1
• Signs of volume overload: peripheral edema, elevated jugular venous pressure, audible rales 2
• Cardiac findings: murmurs, abnormal heart sounds (S3, S4), irregular rhythm 1
• Pulmonary findings: wheezes, decreased breath sounds, signs of hyperinflation (increased AP chest diameter, decreased cricosternal distance) 1

Concurrent Diagnostic Testing

Obtain these tests immediately and simultaneously with clinical assessment:

• 12-lead ECG - Rarely normal in acute cardiac pathology and necessary to exclude ST-elevation MI 2
• Chest radiograph (anteroposterior and lateral) - First-line imaging for dyspnea of unclear etiology, though may be normal in nearly 20% of acute heart failure cases 1, 2
• Laboratory tests: Complete blood count, basic metabolic panel, troponin, brain natriuretic peptide 2, 3
• Spirometry - Essential for confirming COPD diagnosis in a smoker, demonstrating FEV1 <80% predicted with FEV1/FVC ratio <70% 1, 3

Risk Stratification Based on Smoking History

Given the smoking history, prioritize evaluation for:

• COPD - Most likely diagnosis given smoking history and dyspnea; spirometry is mandatory to confirm diagnosis and assess severity 1, 4
• Lung cancer - Weight loss, if present, may indicate occult malignancy 1
• Coronary artery disease - Smoking is major risk factor; dyspnea may represent anginal equivalent 1
• Pulmonary embolism - Consider if acute onset, especially with right flank pain 5

Treatment Initiation While Awaiting Results

Do NOT delay treatment while awaiting complete diagnostic workup - the "time-to-treatment" concept is critical 2

If oxygen saturation <90%:

• Administer supplemental oxygen immediately 2, 3

If signs of respiratory distress:

• Consider non-invasive ventilation 2

If signs of volume overload with systolic BP >140 mmHg:

• Initiate vasodilators and loop diuretics (furosemide) 2

Second-Line Testing if Initial Workup Non-Diagnostic

Proceed to advanced imaging and testing:

• CT chest without IV contrast - Superior for detecting airway disease, interstitial lung disease, pleural abnormalities, and pulmonary embolism 1, 3
• Echocardiography - To evaluate for valvular disease, ventricular dysfunction, pericardial pathology, and pulmonary hypertension 1
• Pulmonary function testing - Comprehensive testing if spirometry suggests restrictive pattern or if diagnosis remains unclear 3

Critical Pitfalls to Avoid

• Do not assume reproducible chest wall tenderness excludes serious pathology - cardiac ischemia and pulmonary pathology can coexist with musculoskeletal pain 1
• Do not rely on normal chest radiograph to rule out pathology - it may be normal in 20% of acute heart failure and does not exclude early interstitial lung disease 1, 2
• Do not assume degree of airflow obstruction can be predicted from symptoms or signs - objective spirometry is mandatory 1
• Recognize that dyspnea etiology is multifactorial in approximately one-third of patients, with cardiac and pulmonary causes being most common 2

Definitive Management Based on Findings

Once diagnosis is established:

• For COPD: Optimize inhaled bronchodilators (beta2-agonists, anticholinergics), consider pulmonary rehabilitation, and address smoking cessation 1, 6, 7
• For cardiac causes: Optimize heart failure medications including diuretics and afterload reduction 2, 3
• For refractory dyspnea: Consider opioids (morphine 2.5-10 mg PO every 2 hours as needed for opioid-naïve patients) as first-line pharmacological treatment 1, 3, 4