Doctors are trying to understand why Covid Patients Coming Off Ventilators Can Take Weeks to Regain Consciousness

In March 2020, New York City’s hospitals filled up with patients desperately ill with Covid-19. In many cases, when their fluid-filled lungs could no longer give them oxygen, doctors sedated them and put them on ventilators.

The patients who recovered were taken off the machines and anesthesia. Within a day or so, their doctors expected them to wake up.

But that’s when the phone of Dr. Nicholas Schiff, a neurologist at Weill Cornell Medicine, started lighting up.

“We’re starting to get all these weird consults,” Dr. Schiff recalled. “People have been liberated from anesthesia after surviving Covid, and they’re not waking up.”

Dr. Schiff, who had spent 25 years treating disorders of consciousness, was perplexed by the influx of unconscious Covid patients. They took weeks, and sometimes months, to wake up. But then they usually regained full consciousness, with no sign of brain damage.

Dr. Schiff and his colleagues have been trying to make sense of this strange phenomenon ever since. On Monday, he published a paper that proposes an answer. And the answer involves turtles.

The brains of unconscious Covid patients bear a striking resemblance to those of turtles that spend the winter encased in ice, argued Dr. Schiff and his collaborator, Dr. Emery Brown, a computational neuroscientist at M.I.T. The turtles survive by putting their neurons into an unusual quiet state that lasts for months. Dr. Schiff and Dr. Brown believe that the combination of Covid and sedatives prompts a similar response in people.

If the theory holds up, it might point to new ways to save people from brain damage: by intentionally putting people into this state, rather than doing so by accident.

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