Trial of High-Dose Blood Thinners in I.C.U. Coronavirus Patients Is Halted

Trial of High-Dose Blood Thinners in I.C.U. Coronavirus Patients Is Halted

Giving anticoagulants to hospitalized Covid-19 patients is routine. But high doses may sometimes do more harm than good, a safety board finds.

A major trial of high-dose blood thinners in critically ill hospitalized Covid-19 patients is being temporarily halted because there appears to be no benefit to the treatment and there may be some harm, the trial’s leaders announced Tuesday.

The independent monitoring board that called for the trial to be paused did not announce what possible harms it had found. High doses of anticoagulants are known to cause uncontrollable bleeding — in places including the inside of the skull, which can be very dangerous.

Trial of High-Dose Blood Thinners in I.C.U. Coronavirus Patients Is Halted

The trial’s leaders are urgently trying to spread word that the trial has been paused, as some hospitals are still aggressively putting their intensive-care patients on high doses of anticoagulants in the belief that the benefits outweigh the risks, whereas the opposite may be true.

“We need to widely advertise this pause in the trial because of the potential for harm,” said Dr. Matthew D. Neal, a surgeon and intensive-care specialist at the University of Pittsburgh Medical Center who is leading one of many teams in the trial.

The teams in the trial, which has enrolled about 3,000 patients in several countries, will examine the data closely to see if enrollment in the branch of the trial focusing on critically ill hospitalized patients can begin again.

Covid-19 is widely known to cause clusters of small blood clots that can block capillaries and cause damage in the lungs, the kidneys, the heart, the brain or other organs and even in the fingers and toes. Low doses of blood thinners are routinely given to hospitalized Covid-19 patients as soon as they are admitted, Dr. Neal said.