Analysis of intensive care populations to select possible candidates for high dependency care

To identify the proportion, and range across intensive care units, of intensive care patients who might potentially be managed on a high dependency unit (HDU) using three different classification systems.

8095 adult patients admitted to 15 intensive care units in the south of England between 1 April 1993 and 31 December 1994 were studied. Patients were identified as potential HDU admissions if their APACHE III derived risk of hospital mortality was < or =10%, if they were categorised as a low risk monitor (LRM) patient using the Wagner risk stratification method, or if they did not require advanced respiratory support (ARS).

4146 patients (51.2%) had an APACHE III derived risk of hospital death of < or =10%, 1687 (20.8%) were classified as LRM, and 3860 (47.7%) did not receive ARS. The values for each intensive care unit ranged from 32.8-63.3% (APACHE III group), 7.2-29.9% (LRM group), and 14.4-68.2% (ARS group). No matter which of the three methods was used, there were significant differences between the 15 units (p<0.0001) with regard to the number of potential HDU patients identified within the scored population.

The percentage of intensive care patients who might be more appropriately managed in a HDU varies considerably between hospitals, and depends upon both local circumstances and the method used to define a high dependency patient. However, whichever method is used, it appears that significant numbers of patients of low dependency status currently fill intensive care beds in the units studied. If these analyses are correct, the perceived national shortage in intensive care beds might be improved by the development of HDUs.