A New York hospital is putting two patients at a time on ventilators intended for one, a stopgap move that reflects the desperate shortage of lifesaving breathing devices during the coronavirus pandemic.

The procedure has never been studied in humans. It was briefly pressed into service in the emergency room of a Nevada hospital that ran short on ventilators during the 2017 mass shooting in Las Vegas and, according to an image on Twitter, in the past few days in Italy. An emergency doctor at SUNY Downstate Health Sciences University in Brooklyn kept four sheep alive for 12 hours in a 2008 experiment, using a jury-rigged ventilator. But another researcher who tested the idea on simulated mechanical lungs in a laboratory said it is too difficult to be practical, even under current circumstances.

“There’s no physician, including myself, who believes this is ideal. This is a doomsday idea,” said Lorenzo Paladino, an associate professor of emergency medicine at SUNY Downstate who performed the 2008 experiment. Rather than choose who can have a ventilator and who will be left to die, “I can do this and maybe keep everyone alive,” he said.

Doctors at Columbia University Irving Medical Center have two patients at a time on some ventilators. Jeremy Beitler, a pulmonary disease specialist at the hospital that is part of the New York-Presbyterian health system, declined to say how many patients are being treated this way.

He said the hospital began the effort in recent days, with the approval of several regulatory agencies and is “scaling up” in response to the shortage.

The ultimate number of additional patients who can be treated this way is unknown, Beitler said. But he cautioned that “this is not a panacea. It’s not going to double the number of ventilators.”

On Friday, President Trump signed an order that requires General Motors to begin manufacturing ventilators, using his authority under the Defense Production Act.