Hepatopulmonary Syndrome

Healthcare providers recognize hepatopulmonary syndrome by a triad of features that appear together:

• Portal hypertension, usually in the setting of liver disease.
• Dilation of the veins entering your lungs (intrapulmonary vascular dilatations).
• Low blood oxygen (hypoxemia).

Most of the time, you’ll already be diagnosed with liver disease and/or portal hypertension when you develop hepatopulmonary syndrome. If not, your healthcare team will take images and blood tests to look for evidence of liver damage. After that, they’ll look at your pulmonary veins and measure the oxygen content of your blood. These tests can demonstrate that vasodilation in your lungs is causing hypoxemia.

What tests are used to diagnose hepatopulmonary syndrome?

Pulse oximetry: Your healthcare team may begin by screening you with a pulse oximetry test, which is simple and noninvasive. You’ve probably had one before. The oximeter is a small electronic device that clips onto the end of your finger. It measures the oxygen saturation in your blood by passing a beam of light through your finger and measuring the amount of light that comes through the other side.

Arterial blood gas: If your pulse oximetry test shows low oxygen saturation, they’ll follow up with a more specific test called an arterial blood gas (ABG). This involves drawing a small blood sample from an artery in your wrist. They’ll measure the blood sample to determine the pressure of oxygen dissolved in your blood (PaO2). This shows how well oxygen transfers from your lungs to your bloodstream.

Contrast echocardiography: An echocardiogram with contrast is the radiology method of choice for diagnosing dilated pulmonary veins. Echocardiography is a type of ultrasound, a technique that uses high-frequency sound waves to produce images of your heart and pulmonary veins. A contrast-enhanced ultrasound introduces a contrast agent into your veins to make them show up better.

When you have a contrast echocardiogram, your technician will inject an agitated saline solution into one of your veins. It’s salt water that’s been infused with a small amount of air to create tiny microbubbles. They’ll watch to see if these bubbles travel from the right side to the left side of your heart (right to left cardiac shunt) in a certain window of time. This can tell them if you have hepatopulmonary syndrome.