Patient selection: hereditary hemorrhagic telangiectasia
Outcome: detection of pulmonary arteriovenous shunt (PAVM)
The initial evaluation:
(1) history of peripheral emboli
(2) oxygen saturation (as measure of right-to-left shunt)
Contrast echocardiography can be performed as the initial imaging study if both of the following are present:
(1) local expertise in identifying a right-to-left shunt.
(2) no evidence of peripheral emboli and oxygen saturation is >= 97%
If the contrast echocardiograph is negative, then the workup for PAVM is negative.
If a contrast echocardiography is not performed, then perform a chest X-ray.
A CT scan is performed:
(1) if the clinical history and chest X-ray are suspicious for PAVM
(2) if the contrast echocardiography is positive.
If the CT scan is negative, then the workup for PAVM is negative.
(1) If patient is an adult, then a CT scan should only be performed in the future if there is a clinical indication to perform it.
(2) If the patient is a child, then screening should be repeated when the patient is an adult since PAVM may enlarge during adolescence.
If the CT scan is positive, then the number, location and extent of the PAVM must be determined.
