What diagnostic tests are recommended for patients presenting with pulmonary edema?

From the Guidelines

For patients presenting with pulmonary edema, the most recommended diagnostic tests include chest X-ray, electrocardiogram (ECG), basic laboratory tests, echocardiography, and pulse oximetry, as these are crucial for determining the underlying cause and guiding treatment. The initial evaluation should prioritize these tests to quickly assess the patient's condition and identify potential cardiac or non-cardiac causes of pulmonary edema.

Key Diagnostic Tests

• Chest X-ray to visualize fluid in the lungs and assess for pulmonary venous congestion or cardiomegaly 1
• Electrocardiogram (ECG) to assess for cardiac ischemia or arrhythmias 1
• Basic laboratory tests including complete blood count, comprehensive metabolic panel, cardiac biomarkers (troponin, BNP or NT-proBNP), and arterial blood gases to evaluate oxygenation status 1
• Echocardiography to assess cardiac function, valvular abnormalities, and ejection fraction, considered the gold standard for evaluating volume status and left ventricular filling pressures 1
• Pulse oximetry for continuous monitoring of oxygen saturation 1 In cases where the diagnosis remains unclear, additional tests may be considered, such as lung ultrasound to diagnose pulmonary edema with good sensitivity and specificity 1, or CT pulmonary angiography to rule out pulmonary embolism.

Additional Considerations

• The choice of diagnostic tests should be guided by the patient's clinical presentation and medical history, with a focus on quickly identifying the underlying cause of pulmonary edema to initiate appropriate treatment.
• Recent studies have highlighted the importance of lung ultrasound in diagnosing pulmonary edema and guiding treatment, with a good sensitivity and specificity 1.
• The use of inferior vena cava diameter and percent change to guide decongestion in acute heart failure patients is still being researched and requires further confirmation 1.

From the Research

Diagnostic Tests for Pulmonary Edema

The following diagnostic tests are recommended for patients presenting with pulmonary edema:

• Chest X-ray (CXR) to evaluate the cardiothoracic ratio, vascular pedicle width, and other radiographic features commonly used to assess pulmonary edema 2
• Echocardiography to assess left ventricular function, cardiac chambers, and valve function 3, 4
• Right cardiac catheterization to measure pulmonary artery occlusion pressure and assess cardiac function 2, 3
• Cardiac magnetic resonance and angiography to evaluate coronary artery disease and pulmonary vein stenosis 3
• Transthoracic and transesophageal echocardiography (TEE) to assess cardiac function and valve function 3

Imaging Manifestations

Pulmonary edema can manifest in various ways on imaging studies, including:

• Hydrostatic pressure edema
• Permeability edema with and without diffuse alveolar damage (DAD)
• Mixed edema where there is both an increase in hydrostatic pressure and membrane permeability 5
• Unilateral pulmonary edema, which can be caused by conditions such as tricuspid valve regurgitation and pulmonary vein stenosis 3

Hemodynamic Monitoring

Invasive hemodynamic monitoring may be necessary in some cases to assess cardiac function and guide treatment, particularly in patients with underlying cardiac disease or those who are critically ill 2, 4