Greg, the article in question tells the story of an SCLS patient in Milan, Italy, who improved twice while going through two episodes in the hospital after the administration of methylene blue, given in the wake of the apparent failure of the medications commonly used to manage such episodes. The article is titled "Systemic Capillary Leak Syndrome: Is Methylene Blue the Silver Bullet?"
Methylene blue is an aromatic chemical compound with several properties. At high concentrations, it has oxidizing-agent properties, and is used by cardiac surgeons when patients have elevated levels of iron in their blood, and thus their hemoglobin has a decreased ability to bind oxygen.
The authors wrote that after many hours of standard treatment without good results, they administered methylene blue and soon after "observed the rapid reversal of hypotension, a concomitant gradual reduction of [hemoconcentration], an increase in urine output, a negative fluid balance, and resolution of edema."
As they admit, however, "the hemodynamic response to methylene blue might have simply faced by chance the natural course of the syndrome, which spontaneously reversed. However, the response we observed was similar in two different occasions, and both times it occurred soon after the administration of the drug."
All I can tell you is that last year I had the unfortunate experience of watching a member of this community go through a severe episode of SCLS, and that after administering just about everything the doctors could think of with the advice of two physicians with experience handling SCLS patients, they too administered methylene blue based on the findings of this very article which had just come out!
Unfortunately, the patient did not improve, suffered major damage to organs, and died several days later. So just as the authors reached their conclusion on the basis of one patient, so I concluded that methylene blue is NOT a silver bullet. Nevertheless, if it can't hurt, I suppose it's worth trying when all else fails.
And please note that nobody is recommending methylene blue as a means of preventing episodes of SCLS.