Bare bones staffing

I'm not involved in staffing in any way, but I wouldn't think it would be wise to only have one staff member present in case of a resuscitation event.

If there are only 1-2 patients in the ICU we are required to have at least 2 RN's present at all times. If an RN has to go off the unit another nurse must be present for relief.

Generally speaking 2 nurses. The only time it was acceptable as 1 nurse 1 aide is a pre-op unit that hadn't been opened yet. But that's a no brained, lol. In the event of a code, 2 RN's for sure at minimum.

We are required to have 2 nurses in our ICU at all times as well, even if there is only 1 patient.

We don't ever have few enough patients in our ICUs/NICUs/PICU to necessitate that low of staffing, but our general policy is that we must have at least two RNs on any unit at any given time. If for some reason a unit only has two RNs they cannot leave the floor unless there is another nurse there for relief. For critical care units that means that they wouldn't be able to go for rapids or codes, so I can't ever see us having less than three RNs on one of those units.

We must have 3 ICU nurses assigned to the unit at all times because our charge nurse responds to codes, leaving 2 nurses in the unit while s/he's away.

Even without codes to consider, how about nurses being able to take the breaks they are legally entitled to. So yes minimum of 2.