How Many ICU Beds Does A Hospital Need?

When a new hospital is built or an existing hospital plans to expand, a key question is “How many ICU beds will we need?“. There is not a one-size-fits-all answer to that question but there are some general principles that guide the number of ICU beds that a hospital requires.

Data from the American Hospital Association’s 2020 publication on U.S. hospital resources reveals that there are 6,146 hospitals in the U.S. Excluding the psychiatric hospitals and federal hospitals, there are 5,198 community hospitals in the United States, of which, 51.4% have intensive care units. Overall, there are 792,417 community hospital beds in the U.S., of which 13.5% are ICU beds. The overall make-up of U.S. community hospital beds is:

• 792,417 total hospital beds

• 55,663 medical/surgical ICU beds

• 15,160 cardiac care unit beds

• 7,419 other ICU beds

• 22,721 neonatal ICU beds

• 5,115 pediatric ICU beds

• 25,157 step down unit beds

Location, Location, Location

Intensive care units are not uniformly distributed in the United States. Many smaller hospitals lack ICUs and consequently, more than 50% of U.S. counties do not have any ICU beds. Most ICU beds are found in metropolitan areas (defined as > 50,000 population) or micro metropolitan areas (defined as 10,000 – 49,999 population:

• 94% of ICU beds are in metropolitan areas

• 5% of ICU beds are in micro metropolitan areas

• 1% of ICU beds are in rural areas

There are a number of reasons for the paucity of ICU beds in rural areas but perhaps the most important reason is that an ICU is more than just a bed and a ventilator, an ICU requires critical care-trained nurses, advanced pharmacy support, 24-hour respiratory therapy, and physicians with critical care skills. Smaller hospitals in rural areas generally cannot support all of these specialized personnel to provide care for a relatively small number of ICU beds.

Although the overall average percentage of hospital beds in the U.S. that are ICU beds is 13.5%, because many rural hospitals lack ICUs, the percentage of ICU beds in metropolitan hospitals is necessarily higher than 13.5%. This is particularly true for academic medical centers and pediatric hospitals that function as tertiary care facilities with the result that these hospitals admit more complex patients who more often require ICU services. So, for example, in Columbus, Ohio, between the 3 major hospital systems plus the children’s hospital, there are 3,873 hospital beds. Of these, 572 (15%) are ICU beds.

Another way of analyzing ICU bed use is by expressing the number of ICU beds per 10,000 population. This can be misleading, however, because many rural areas will send most of their ICU-level patients to nearby metropolitan areas with the result that the larger metropolitan areas will have more ICU beds per capita. Nevertheless, in an analysis by the Washington Post, the major metropolitan areas in Ohio varied significantly in ICU beds per 10,000 population:

• 6.3 Toledo

• 5.3 Cleveland

• 5.0 Cincinnati

• 5.0 Dayton

• 4.7 Akron

• 4.4 Canton

• 3.6 Columbus

What About Utilization?

The Society of Critical Care Medicine recently analyzed ICU occupancy. Overall in the United States, the ICU occupancy rate is 66.6% for adult ICUs, 61.6% for pediatric ICUs, and 67.7% for neonatal ICUs. One of reasons that these percentages seem low is that there can be wide swings in occupancy and a hospital needs to have sufficient resources to accommodate high-census times. Furthermore, ICU occupancy is generally based on the midnight census in a hospital, that is, the number of patients in a bed at midnight. Because patients usually do not get transferred out of ICUs until early afternoon (after the physicians make morning rounds) but patients get transferred into ICUs continuously throughout the day, the 66.6% occupancy rate at midnight for adult ICUs underestimates the peak occupancy for ICUs at noon which is considerably higher.

When a hospital’s ICU occupancy rate is low, the ICU tends to harbor less acute patients. Conversely, when a hospital’s ICU occupancy rate is high, higher acuity patients often get admitted to non-ICU locations such as step-down units. Consequently, a patient with a COPD exacerbation requiring non-invasive ventilation with BiPAP but not requiring intubation with mechanical ventilation would be admitted to an ICU bed when there is adequate ICU capacity but might be admitted to a step-down bed when there is insufficient ICU capacity.

So, how many ICU beds does a hospital need?

If we start with the U.S. average, then a hospital needs 13.5% of its beds to be ICU beds. Hospitals in larger cities need a higher percentage whereas hospitals in small towns need a lower percentage. Within larger cities there will also be variation: tertiary care hospitals and children’s hospitals will require a higher percentage than other hospitals in metropolitan areas.

In deciding whether to expand ICUs, a hospital should also look at its ICU occupancy rate. If the average occupancy rate is < 66% then the hospital likely does not need additional ICU beds. However, if the occupancy rate is > 66%, then ICU bed expansion may be warranted.

Lastly, the hospital should examine the acuity of patients in the ICU when determining whether ICU beds should be increased. A 2013 study of ICU occupancy and ventilator use in the U.S. found that the mean percentage of ICU patients on a ventilator at any given time was 40%. If a hospital’s ICU ventilated patient percentage averages less than this, then it may not need additional ICU beds. However, if the percentage of ICU patients on a ventilator is > 40%, then more ICU beds may be needed.

A hospital needs to have the correct number of intensive care unit beds to support its operating rooms and general nursing units. There also needs to be sufficient ICU beds regionally to support the community’s need to care for the sickest patients. ICUs are expensive and the specialized staff it takes to care for patients in ICUs are even more expensive. However, the DRG reimbursement for these patients is high and so ICUs can be financially lucrative for a hospital. When hospitals plan bed expansion, it must be done with the right balance of ICU to non-ICU beds in mind.

October 10, 2020