From the Guidelines
For a patient presenting with shortness of breath (dyspnea), initial laboratory tests should include complete blood count, basic metabolic panel, cardiac enzymes (troponin), brain natriuretic peptide (BNP), D-dimer, arterial blood gas analysis, and chest X-ray, as recommended by the most recent guidelines 1. Pulse oximetry should be performed immediately to assess oxygen saturation, and supplemental oxygen should be provided if saturation is below 92% 1. An electrocardiogram (ECG) should be obtained to evaluate for cardiac causes. Initial interventions should focus on stabilizing the patient with positioning (often upright to ease breathing), oxygen therapy via nasal cannula (2-6 L/min) or mask (10-15 L/min) depending on severity, and establishing IV access. If bronchospasm is suspected, administer albuterol 2.5 mg via nebulizer or 4-8 puffs via metered-dose inhaler with spacer every 20 minutes for up to three doses. For severe respiratory distress, consider non-invasive positive pressure ventilation (CPAP starting at 5 cmH2O or BiPAP with inspiratory pressure 8-12 cmH2O and expiratory pressure 3-5 cmH2O) or prepare for endotracheal intubation if respiratory failure is imminent. These tests and interventions are crucial because dyspnea can result from various underlying conditions including cardiac, pulmonary, metabolic, or psychological disorders, and prompt identification of the cause guides appropriate treatment while supporting respiratory function. The use of BNP or NT-proBNP measurement can improve the diagnostic accuracy compared to standard clinical judgment alone in the diagnosis of acute heart failure syndrome among patients presenting to the ED with acute dyspnea 1. In addition, the measurement of troponin levels can help identify patients with acute coronary syndrome, which is a common precipitating factor for acute heart failure 1. Overall, a comprehensive approach to the evaluation and management of dyspnea is essential to ensure optimal patient outcomes.
Some key points to consider when evaluating a patient with dyspnea include:
- Assessing the patient's oxygen saturation and providing supplemental oxygen as needed 1
- Evaluating the patient's cardiac function using ECG and echocardiography 1
- Measuring BNP or NT-proBNP levels to aid in the diagnosis of acute heart failure syndrome 1
- Assessing the patient's volume status and providing diuretic therapy as needed 1
- Considering the use of non-invasive positive pressure ventilation or endotracheal intubation in patients with severe respiratory distress 1
From the Research
Initial Laboratory Tests for Shortness of Breath
The initial laboratory tests for a patient presenting with shortness of breath (dyspnea) may include:
- Complete blood cell count (CBC) to evaluate for anemia, which can cause shortness of breath 2, 3
- Blood measurements of B-type natriuretic peptide (BNP) and N-terminal-proBNP (NT-proBNP) to identify patients with congestive heart failure (CHF) 4, 5, 6
- Arterial blood gas (ABG) analysis to assess oxygenation and ventilation
- Electrocardiogram (ECG) to evaluate for cardiac arrhythmias or ischemia
- Chest radiograph to evaluate for pulmonary edema, pneumothorax, or other lung abnormalities
Interventions for Shortness of Breath
Interventions for a patient presenting with shortness of breath may include:
- Oxygen therapy to improve oxygenation 4
- Non-invasive positive pressure ventilation (NIPPV) or mechanical ventilation for severe respiratory distress
- Diuretics to reduce pulmonary edema in patients with CHF 6
- Vasopressors or inotropes to support cardiac function in patients with cardiogenic shock
- Anticoagulation therapy for patients with pulmonary embolism (PE) 5
- Blood transfusions for patients with severe anemia 2, 3
Biomarkers for Prognosis
Biomarkers such as NT-proBNP and BNP can be used to predict prognosis in patients with acute respiratory distress syndrome (ARDS) and PE: