From the Guidelines
A comprehensive workup for shortness of breath (SOB) should begin with a thorough history and physical examination to identify potential causes, followed by initial diagnostic testing including a chest X-ray, complete blood count, basic metabolic panel, and electrocardiogram, as recommended by recent guidelines 1. The initial assessment should include evaluating vital signs such as oxygen saturation, respiratory rate, heart rate, blood pressure, and temperature.
- For patients with suspected cardiac causes, ordering cardiac biomarkers (troponin, BNP) and considering echocardiography is essential, as it provides incremental diagnostic information with respect to common cardiovascular causes, including acute heart failure, valvular heart disease, and coronary artery disease 1.
- If pulmonary embolism is suspected based on risk factors or presentation, obtaining a D-dimer test and considering CT pulmonary angiography for positive or high-risk cases is crucial, as it can help identify life-threatening conditions that require immediate attention.
- For suspected respiratory causes, performing pulmonary function tests and arterial blood gas analysis can help diagnose underlying conditions such as chronic obstructive pulmonary disease (COPD) or pneumonia.
- In cases of suspected infection, collecting appropriate cultures and considering procalcitonin levels can aid in identifying the cause of SOB and guiding antibiotic therapy. Additional testing may include CT chest for interstitial lung disease, sleep studies for sleep-disordered breathing, or cardiopulmonary exercise testing for unclear etiology, as recommended by the European Society of Cardiology 1. Treatment should target the underlying cause while providing supportive care, such as supplemental oxygen for hypoxemia (maintain SpO2 >90%), bronchodilators for bronchospasm (albuterol 2.5mg nebulized or 2-4 puffs MDI every 4-6 hours), and diuretics for volume overload (furosemide 20-40mg IV/PO), as outlined in the guidelines for acute heart failure management 1. This systematic approach ensures efficient diagnosis and management of SOB by addressing the most common and life-threatening causes first while tailoring further workup based on initial findings and clinical suspicion.
From the Research
Guideline Directed Algorithm for Workup of Shortness of Breath (SOB)
The management of acute shortness of breath requires a prompt and systematic approach to identify the underlying cause and provide appropriate treatment 2. The following steps outline a guideline-directed algorithm for the workup of SOB:
- Initial Assessment: Begin with a detailed history and physical examination to identify potential causes of SOB 3.
- First-Line Tests: Order initial tests, including:
- Complete blood count
- Basic chemistry panel
- Electrocardiography
- Chest radiography
- Spirometry
- Pulse oximetry 3
- Imaging: Use standard chest X-ray (CXR) to evaluate for cardiac and pulmonary causes of dyspnea, such as pulmonary embolism, pneumothorax, and pulmonary edema 4.
- Pulmonary Ultrasound and Pulse Oximetry: Consider using pulmonary ultrasound and pulse oximetry as alternative diagnostic tools in low-resource settings or when traditional radiographic and oxygenation evaluation are not available 5.
- Second-Line Tests: If no cause is identified, consider second-line noninvasive testing, including:
- Echocardiography
- Cardiac stress tests
- Pulmonary function tests
- Computed tomography scan of the lungs 3
- Invasive Tests: If necessary, perform more invasive tests in collaboration with specialty help 3.
- Treatment and Management: Focus on correctly identifying the underlying disease process, optimizing recovery, and improving dyspnea symptoms 3. Use the six-minute walk test to measure the effect of ongoing intervention 3.
Differential Diagnosis
Consider the following potential causes of SOB: