Dyspnea

KEY FEATURES

Essential Inquiries

• Fever; cough; risk of infection with SARS-CoV-2; chest pain

• Vital signs; pulse oximetry

• Chest and cardiac examination

• Chest radiography

• Arterial blood gas result (in selected patients)

General Considerations

• Defined as a subjective experience or perception of uncomfortable breathing

• Can result from

  • Increased mechanical effort of breathing (eg, asthma, chronic obstructive pulmonary disease [COPD], restrictive lung disease, respiratory muscle weakness, Parkinson disease, obesity hypoventilation syndrome)

  • Alveolar lung disease (eg, pulmonary edema, pneumonia, alveolar proteinosis)

  • Interstitial lung disease (eg, hypersensitivity pneumonitis)

  • Compensatory tachypnea (eg, hypoxemia or acidosis)

  • Primary pulmonary vasculopathy (pulmonary hypertension)

  • Psychogenic conditions

CLINICAL FINDINGS

Symptoms

• Rapid onset, severe dyspnea in the absence of other clinical features should raise concern for

  • Pulmonary emboli (PE)

  • Increased left ventricular end-diastolic pressure (LVEDP)

  • Pneumothorax

• PE should always be suspected when cause of dyspnea is not apparent or when a patient with new dyspnea reports

  • A recent history (previous 4 weeks) of prolonged immobilization or surgery

  • Estrogen therapy

  • Other risk factors of deep venous thrombosis (eg, previous history of thromboembolism, cancer, obesity, lower extremity trauma)

• Silent myocardial infarction (MI)

  • Occurs more frequently in persons with diabetes and women

  • Can result in increased LVEDP, acute heart failure (HF), and dyspnea

• Spontaneous pneumothorax

  • Usually accompanied by chest pain

  • Occurs most often in thin, young males, or in those with underlying lung disease

• When cough and fever are present,

  • Pulmonary disease (particularly infections) is the primary concern

  • However, myocarditis, pericarditis, and septic pulmonary emboli can also present in this manner

• Chest pain

  • Should be further characterized as acute or chronic, pleuritic, or exertional

  • Although acute pleuritic chest pain is the rule in acute pericarditis and pneumothorax, most patients with pleuritic chest pain in the outpatient clinic have pleurisy due to acute viral respiratory tract infection

  • Periodic chest pain that precedes the onset of dyspnea is suspicious for myocardial ischemia or pulmonary emboli

• Wheezing

  • Most cases due to acute bronchitis

  • Other causes include new-onset asthma, foreign body, and vocal fold dysfunction

• Interstitial lung disease and pulmonary hypertension should be considered in patients with symptoms (or history) of connective tissue disease

• Pulmonary lymphangitic carcinomatosis should be considered if a patient has malignancy

• When a patient reports prominent dyspnea with mild or no accompanying features, consider

  • Chronic PE

  • Noncardiopulmonary causes of impaired oxygen delivery (anemia, methemoglobinemia, cyanide ingestion, carbon monoxide)

  • Metabolic acidosis

  • Panic disorder

  • Neuromuscular disorders

• Platypnea-orthodeoxia syndrome

  • Characterized by dyspnea and hypoxemia on sitting or standing that improves in the recumbent position

  • May be caused by an intracardiac shunt, pulmonary vascular shunt, or ventilation-perfusion mismatch

• Hyperthyroidism can cause dyspnea from

  • Increased ventilatory drive

  • Respiratory muscle weakness

  • Pulmonary hypertension

• Patients who recover from their initial COVID-19 infection may have persistent dyspnea as part of the “long COVID” syndrome