They key is how many of them are occupied at any time.
The capacity of the ICU over time is pretty straight forward. Its the number of beds, the average stay, and length of time to turn over the bed (cleaning, stocking, and staffing.)
A normal stay in ICU is something like 3-5 full days. The CV ICU stay is about twice that. And it includes breathing machines and other life assisting machines.
The hospital could turn those rooms over in an hour (pretty remarkable time to sterilize the room.). In any decent sized city, with 36 ICU rooms per hospital, the hospital would be gummed up in a week.
If you think about it, there are usually no empty rooms. So from day 1, the average stay is going to start doubling because for every 3-5 day stay that leaves is going to be replaced by a 10-14 day stay. In less than a week you would have NO turnover for 5-7 days.
And at the same time the regular patients stack up. And at the same time the CV patients are showing up.
And you overflow to another hospital...for about two days. Then they are in the same position.
Where are you going to put ALL the new ICU patients?
Thats how easily this can happen. It really doesnt take much.
Operations fill the ICUs.
Delay the operations, when possible, and many beds will be freed.
Yeah, it requires discretion.