The device, called CytoSorb, is about the size of a drinking glass and is filled with coarse polymers, each roughly the size of a grain of salt. Every grain, or bead, has millions of pores and channels that add up to a surface area of roughly seven football fields and filter out molecules roughly the size of cytokines. One cartridge can purify an entire body’s blood volume roughly 70 times in a 24-hour period.
Bigger objects like cells go around the beads and are unaffected, and smaller things like electrolytes go straight through, said Dr. Phillip Chan, the chief executive of CytoSorbents Corporation, which makes the device. CytoSorb may also remove some proteins that the body needs.
But “in a life-threatening illness when you have a cytokine storm,” Dr. Chan said, “it’s more or less a race to remove what will kill you versus the temporary inconvenience of removing things that your body manufactures all the time anyway.”
In Europe, where CytoSorb has been commercially available since 2013, it has been used more liberally. But in the United States, the device had been allowed only for patients who had exhausted all other options. Even now, during the pandemic, its use is authorized only in coronavirus patients who are critically ill, with imminent or confirmed respiratory failure.
Dr. Stephan Ziegeler, who leads a specialized pulmonary intensive care unit at a hospital in Ibbenbüren, Germany, has so far treated eight people with CytoSorb. (Since 2018, he has received speaking fees from CytoSorb’s manufacturer, totaling 5,000 euros, or about $5,600.) Of these people, three have been discharged, three are being weaned off ventilation and two have died.
Patients with bacterial sepsis typically need a maximum of three cartridges — one per day at $1,200 — but coronavirus patients have such astronomical levels of cytokines, Dr. Ziegeler said, that some have needed dozens of cycles, with two fresh cartridges per day.
“It seems that Covid-19 has a prolonged cytokine storm — a prolonged, really effective inflammatory state compared to other sepsis states,” he said.