The story, all Italian, told by the BBC (here the article) is exciting.
A hospital in Brescia (north of Italy) had 250 patients with coronavirus in intensive care, and its valve supplier was unable to produce all the valves necessary to cover the need. When an Italian journalist realized this, she put the hospital in contact with the General Manager of Isinnova, a 3D printer company. They went to the hospital for a quick visit and, three hours later, they had produced and tested a 3D printed prototype on a patient.