Changes in Intensive Care Unit Performance Measures Associated With Opening a Dedicated Thoracic Surgical Progressive Care Unit

Objectives: To determine the effect of the introduction of a specialty-specific progressive care unit (PCU) on the intensive care unit (ICU) to which relatively low-acuity patients had previously been admitted.

Design: Retrospective cohort study.

Setting: The thoracic (noncardiac) surgical ICU of a tertiary referral institution.

Patients: Four thousand fifty-three patients admitted to the ICU after thoracic surgery between October 1994 and December 2003.

Interventions: None.

Measurements and Results: The institutional Acute Physiology and Chronic Health Evaluation (APACHE) III database was searched to compare the number of admissions, severity of illness, mortality, and other aspects of care for periods before and after the introduction of the PCU. Patients in the post-PCU group were more severely ill by APACHE criteria. The ICU mortality rates for the periods before and after the introduction of the PCU were 1.14% (32/2,801 patients) and 7.27% (91/1,252 patients), respectively. The performance of the ICU appeared to be worse in the period after the opening of the PCU. The ICU- and hospital-customized standardized mortality ratio increased from 0.68 (95% confidence interval [CI], 0.47-0.96) in the pre-PCU group to 1.20 (95% CI, 0.96-1.47) in the post-PCU group and from 0.83 (95% CI, 0.66-1.03) to 1.24 (95% CI, 1.05-1.46).

Conclusions: The introduction of a nonintensivist-directed PCU to care for thoracic surgical patients had a significant impact on the parent ICU. Of concern is that outcome and quality measures appeared to worsen and ICU readmission rate increased.

Key words: intensive care unit, Acute Physiology and Chronic Health Evaluation, prognosis, progressive patient care, thoracic surgery