On April 2, a plane left China with 1.2 million N95 masks. In normal, pre-covid-19 times, that would be a big stash, according to an article on The Washington Post website.
Most hospitals bought a few thousand N95s per year. But when the number of covid-19 patients exploded, a million masks wasn’t that many. Health and Human Services Assistant Secretary Robert Kadlec said in February that the U.S. would need 3.5 billion N95s in a serious pandemic.
According to the Centers for Disease Control and Prevention, the median hospital stay of a surviving Covid-19 patient is 10 to 13 days. That works out to between 350 and 520 N95s per patient.
In mid-May, as emergency supply lines increased and reuse of hospital garb has become common, the answer is somewhere in between, according to the article.