What history and physical exam components are essential to evaluate shortness of breath?

Comprehensive Evaluation of Shortness of Breath

The essential components for evaluating shortness of breath include a detailed history focusing on onset, duration, and triggers of symptoms, followed by a thorough physical examination with particular attention to cardiopulmonary systems, and appropriate diagnostic testing guided by initial findings.

History Components

Timing and Characteristics

• Onset and duration: Acute vs. chronic, sudden vs. gradual onset 1
• Temporal patterns: Intermittent vs. continuous, relation to time of day
• Quality of breathing discomfort: Ask patients to describe the sensation in their own words
  • "Chest tightness" may suggest bronchoconstriction 1
  • "Air hunger" or "inability to get deep breath" often indicates restrictive mechanics (heart failure, pulmonary fibrosis) 1
  • "Effort" or "suffocation" sensations may be seen in panic disorder 1

Aggravating and Alleviating Factors

• Exercise tolerance: Distance/activity that precipitates symptoms
• Positional changes: Orthopnea, platypnea
• Environmental triggers: Cold air, allergens, irritants
• Relation to specific activities: Sports, occupational exposures

Associated Symptoms

• Chest pain (cardiac vs. pleuritic)
• Cough (productive vs. non-productive)
• Wheezing or stridor
• Fever, weight loss
• Lower extremity edema
• Palpitations

Risk Factors and Exposures

• Occupational history: Asbestos or other occupational exposures 1
• Smoking history: Current, former, pack-years
• Environmental exposures: Home, work, hobbies
• Medication use: Beta-blockers, methotrexate, amiodarone
• Travel history: Recent travel, altitude exposure

Physical Examination Components

Vital Signs

• Respiratory rate: Tachypnea suggests increased respiratory drive
• Oxygen saturation: Both at rest and with ambulation (exercise desaturation) 2
• Heart rate: Tachycardia may indicate cardiac etiology or respiratory distress
• Blood pressure: Hypertension or hypotension
• Temperature: Fever suggesting infectious process

General Inspection

• Work of breathing: Use of accessory muscles, intercostal retractions
• Body habitus: Obesity, cachexia, barrel chest
• Cyanosis: Central vs. peripheral
• Mental status: Anxiety, confusion (hypoxemia)

Chest Examination

• Inspection: Chest wall deformities, asymmetric movement
• Palpation: Tactile fremitus, chest expansion
• Percussion: Dullness (effusion, consolidation), hyperresonance (emphysema)
• Auscultation:
  • Lungs: Wheezes, crackles, rubs, diminished breath sounds, prolonged expiration
  • Heart: Murmurs, gallops, rubs, irregular rhythm
  • Distinguish inspiratory stridor from expiratory wheezing to differentiate upper airway disorders from lower airway disease 1

Additional Systems

• Extremities: Edema, cyanosis, clubbing
• Neck: JVD, tracheal position, thyromegaly
• Abdomen: Hepatomegaly, ascites
• Neurological: Muscle strength, diaphragmatic function

Diagnostic Algorithm

Initial Testing (Based on History and Physical)

1. Pulse oximetry: Both at rest and with ambulation 2
2. Chest radiography: First imaging study for all patients with dyspnea 2
3. ECG: To assess for cardiac causes 2
4. Basic laboratory tests: CBC, basic metabolic panel, cardiac biomarkers (troponin, BNP/NT-proBNP) 2

Further Testing Based on Initial Findings

• If normal chest X-ray but persistent symptoms:

  • High-resolution CT of chest (especially with oxygen desaturation during ambulation) 2
  • Spirometry to assess for airflow obstruction or restriction 2

• If abnormal chest X-ray:

  • Pattern-specific follow-up (infiltrates, effusions, masses)
  • Consider bronchoscopy for central lesions

• If cardiac etiology suspected:

  • Echocardiography to assess cardiac structure and function 2
  • Consider stress testing if ischemia suspected

Specialized Testing for Unclear Cases

• Cardiopulmonary exercise testing (CPET): Differentiates cardiac from pulmonary causes of dyspnea 1, 2
• Six-minute walk test: Assesses functional capacity and oxygen desaturation 2
• Exercise challenge testing: For suspected exercise-induced bronchoconstriction 1
• Bronchoscopy with bronchoalveolar lavage: For suspected interstitial lung disease 2

Common Pitfalls to Avoid

1. Overlooking non-cardiopulmonary causes: Anemia, acidosis, neuromuscular disorders
2. Attributing dyspnea to a single cause when multiple factors may contribute 2
3. Missing upper airway obstruction: Foreign bodies can mimic other conditions 3
4. Failing to recognize exercise-induced bronchoconstriction in patients with normal resting studies 1
5. Overlooking interstitial lung disease on plain radiographs (may require HRCT) 2
6. Not considering psychological causes like anxiety or panic disorder when organic causes are ruled out 1

Special Considerations

• Linguistic and cultural differences may affect how patients describe their breathing sensations 1
• Multifactorial etiology is common in up to one-third of dyspnea cases 2
• Deconditioning should be a diagnosis of exclusion after ruling out pathological causes
• Exercise desaturation (e.g., from 98% to 92%) is clinically significant even with normal resting studies 2

By systematically addressing these components in the history and physical examination, clinicians can develop a focused differential diagnosis and appropriate testing strategy for patients presenting with shortness of breath.