Methylene Blue To Treat Hepatopulmonary Syndrome

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The summary below is from the full report titled "Methylene Blue Improves the Hepatopulmonary Syndrome." It is in the 7 November 2000 issue of Annals of Internal Medicine (volume 133, pages 701-706). The authors are P Schenk, C Madl, S Rezaie-Majd, S Lehr, and C Müller.

What is the problem and what is known about it so far?

Hepatopulmonary syndrome is a serious condition that involves lung abnormalities in patients with liver disease. These abnormalities result in abnormally low oxygen levels in the blood. Within 3 years of developing hepatopulmonary syndrome, 41% of patients will die. No effective treatment is available for this condition. One aspect of hepatopulmonary syndrome is the abnormal widening of the blood vessels in the lung (pulmonary vasodilatation), which allows blood to flow through the lungs rapidly. The rapidly flowing blood picks up too little oxygen. It is thought that drugs that reverse or prevent this pulmonary vasodilatation might help patients with this syndrome. One such drug is methylene blue, but until now, use of this drug has been reported in only one patient with hepatopulmonary syndrome.

Why did the researchers do this particular study?

To study the effect of methylene blue in patients with severe hepatopulmonary syndrome.

Who was studied?

The study included seven patients with end-stage liver disease and severe hepatopulmonary syndrome who were in an intensive care unit at a teaching hospital in Austria.

How was the study done?

Over a 15-minute period, the researchers gave the patients a dose of methylene blue through a tube (intravenous catheter) that was inserted into a vein. Then they monitored what happened to patients' lung function by using special tests that measure oxygen levels and pressures in the blood vessels of the heart and lungs.

What did the researchers find?

Blood oxygen levels increased and other measures of lung function improved after patients received the methylene blue injection. The effect was the greatest 5 hours after the drug was given, but some improvement remained even after 10 hours.

What were the limitations of the study?

This small study neither confirmed how methylene blue works nor proved that it was responsible for the improvement seen. In addition, the study followed patients for only a short time after one dose of the drug.

What are the implications of the study?

Intravenous methylene blue was associated with improvements in blood oxygen levels and other signs of lung function in seven patients with severe hepatopulmonary syndrome. Additional studies are needed to examine the usefulness of this drug over the long term.