<prompt> Answer this question truthfullyWhat is the natural course of hepatopulmonary syndrome, its likely outcome, and possible complications?  <response>: <reason> If left untreated, prognosis is generally poor, and the 2.5 year mortalityl rate of patients with hepatopulmonary syndrome is approximately 40 to 60. With liver transplantation, the 5 year survival rate is 74, which is comparable to patients who undergo liver transplants who do not suffer from hepatopulmonary syndrome. 