Some overrun Italian hospitals shared ventilators for coronavirus patients, but there's been little experience with the practice in the U.S. so far. At least one hospital in hard-hit New York has reportedly started doing so recently, and Las Vegas hospitals briefly deployed the strategy in 2017 following the deadliest mass shooting in U.S. history.

Some groups representing critical care providers last week warned against ventilator splitting, arguing "it cannot be done safely with current equipment."

The last-resort measure offered by Trump health officials runs counter to the administration’s previous assurances that states would have enough ventilators, despite governors’ consistent warnings about shortages. President Donald Trump has criticized New York Gov. Andrew Cuomo’s request for 30,000 ventilators, and Deborah Birx, the coordinator of the White House coronavirus task force, turned heads in the public health community last week when she downplayed concerns about ventilator shortages.

“To say that to the American people, to make the implication that when they need a hospital bed, it’s not going to be there, or when they need that ventilator, it’s not going to be there — we don’t have evidence of that right now,” Birx said last Thursday.

Ford and GE on Monday announced they would team up to make 50,000 ventilators in the next three months, but it will take weeks to ramp up to wide-scale production. Meanwhile, Gov. John Bel Edwards of Louisiana has warned his state could run out of ventilators within a week.

Trump administration health officials in Tuesday’s letter also stressed other strategies meant to reduce the need for ventilators, including the cancellation of elective surgeries and ensuring states' requests for equipment from the national stockpile are "judicious" and "data-driven."