Skip to main content

Effects of establishing an intermediate care unit: changes in case mix at a cardiologic-pulmonary ICU


Intermediate care or step-down units are widely introduced to improve utilization of critical care resources, to smooth transition for patients transferred from the ICU and to reduce the ICU length of stay. However, the effect that intermediate care units can have on the case-mix of specific ICUs and how this relates to measures of morbidity, mortality and severity of illness is not clear.


We analyzed data from two cohorts of ICU patients staying >24 hours, which were prospectively collected from March 2000 to April 2001 and from March 2006 to April 2007 in a 12-bed cardiologic–pulmonary ICU in a tertiary-care center university hospital. Two intermediate care step-down units were introduced in between, with the units fully operational in 2005. We compared demographics, measures of resource use, severity of illness and mortality.


Totals of 705 and 389 patients (-45%) were admitted in 2000/01 and in 2006/07. There were no significant differences in gender distribution or age (68% vs. 64% male, mean age 64 ± 13.5 vs. 66 ± 14.2 years). While acute coronary syndrome remained the most common diagnosis (33% vs. 32%), a larger proportion of patients were admitted due to cardiogenic shock (8% vs. 26%) and sepsis (2% vs. 8%). More patients were admitted after out-of-hospital cardiac arrest (8% vs. 25%) and on MV (14% vs. 35%). ICU mortality increased from 9% to 22% with subsequent mortality outside the ICU equal at 4% for both cohorts. The mean Sequential Organ Failure Assessment score on the admission day increased from 2.1 ± 2.9 to 7.6 ± 2.8 for survivors and 7.7 ± 4.8 to 10.8 ± 3.0 for the dead. ICU length of stay (LOS) increased from 5 ± 10.2 to 8 ± 12.2 days for survivors and 7 ± 10.8 to 12 ± 14.8 days for the dead, while hospital LOS was nearly unchanged regardless of survival status. Physician staffing and nurse-to-patient ratios did not change (two physicians and 1:3 during days and one physician and 1:4 during nights).


The implementation of an intermediate care unit led to a significant change in the ICU case-mix with increased ICU LOS, mortality and severity of illness of patients admitted. Effects on nurse workloads, team job satisfaction, and critical care triage should be further analyzed to optimize the treatment of these critically ill patients.

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

Kersten, A., Engelmann, M., Lepper, W. et al. Effects of establishing an intermediate care unit: changes in case mix at a cardiologic-pulmonary ICU. Crit Care 13 (Suppl 1), P477 (2009).

Download citation

  • Published:

  • DOI:


  • Acute Coronary Syndrome
  • Critical Care
  • Sequential Organ Failure Assessment
  • Cardiogenic Shock
  • Sequential Organ Failure Assessment Score