That's a great question.

I found this plot from Arizona Department of Public Health.'Hospital Bed Usage & Availability' sub-tab 'Number of Intensive Care Unit Available and In-use at Arizona Hospitals.'

https://azdhs.gov/preparedness/epidemiology-disease-control/...

Everything is reported in percentages, so I don't know how the absolute number of beds shifted as a result of temporary increases in ICU capacity.