In this May 3, 2021, file photo, Hennepin County Medical Center patient John Grubb, of St. Michael, hugs and says goodbye to several of his caregivers as his wife, Kelly, lower right, looks on before he is discharged from the hospital in Minneapolis, after spending 81 days on the ECMO heart-lung bypass machine, which has been the treatment of last resort in COVID-19 care. (David Joles/Star Tribune via AP, File)