1. What is the test of choice for diagnosis of hepatopulmoanry syndrome?
a) MR angiography
b) Liver ultrasound
c) Contrast echocardiography
d) CT angiography
2. What is the primary treatment for HPS?
a) Liver transplant
b) Oxygen supplementation
c) Milrinone infusion
3. True or false: The more severe the liver disease, typically the more severe the hepatopulmonary syndrome.
ANSWERS & EXPLANATIONS
1. C. While CT and MR angiography may prove useful in evaluating the pulmonary vasculature, contrast echocardiography with agitated saline is the test of choice for diagnosing hepatopulmonary syndrome. Typically, the bubbles produced by agitation should be lodged in the pulmonary capillaries. However, due to dilatation of these capillaries (leading to relative intrapulmonary shunt and hypoxemia), the bubbles are able to pass through and can be visualized in the left side of the heart within 3-6 cardiac cycles
2. A. While pentoxifylline has been investigated as a therapy to reduce NO production and thereby potentially reduce pulmonary vascular vasodilatation, its efficacy is unclear at this point in time. Supplemental oxygen is used to support the patient but liver transplant is the primary treatment for HPS and are given exception points for liver transplant consideration.
3.B False, there is no association between the severity of liver disease and the severity of hepatopulmonary syndrome