I work in a large inner city ED, we usually only board our ICU patients because our ICUs tend to be full even though we have about 50 ICU beds. Patients who are intubated tend to get a bed within a few hours because they shuffle patients around to accomodate them, but it's relatively common for me to have one or two ICU/CCU or stepdown patients that have been waiting in the department for 24+ hours. Also this doesn't effect our ratio at all, we're still expected to care for 6-8 patients with the ICU included