The effect of surgical ICU triage patterns on differing severity adjusted outcomes in France and the United States

Abstract

Introduction: Surgical patients treated in French intensive care units (ICU's) appear to have higher mortality rates than patients in the United States. We hypothesized that this may be due to the French practice of not transferring dying patients from the ICU. We wished to determine if the different mortality rates could be explained by transfer practices for dying patients or other factors such as severity of illness.

Methods: Flowsheet data for 6,787 consecutive surgical ICU (SICU) patients from our institution over a 31 month period was entered into an ICU Clinical Information System which calculated the Day 1 Simplified Acute Physiology Score (SAPS) for each patient upon admission to the SICU. SICU and overall hospital mortality data were matched with severity data and the complete data set was analyzed against results for 2,604 surgical patients in French ICU's. Since terminally ill patients in France are not transferred to floor care, we also compared the French ICU mortality rate with both our SICU mortality rate and combined SICU and surgical floor mortality rates.

Results: Our overall SICU mortality was 1.7% and our combined SICU and hospital mortality was 4.2%, while the French ICU mortality was 14.1%. The French ICU's had more patients with higher severity of illness as measured by SAPS. When the effects of ICU transfer practices and severity of illness were considered, there were no mortality differences seen among patients admitted to the different units after elective surgery. Significant differences in mortality were seen when patients admitted emergently were studied.

Conclusions: The differences in severity adjusted ICU mortality between French ICU's and our SICU are explained by different triage practices for terminally ill patients following elective ICU admission. These triage differences do not fully explain the mortality differences seen among patients emergently admitted to the ICU. Other factors such as the presence of trauma, ICU staffing practices, patient mix or other unidentified factors may be responsible for the severity adjusted differences in mortality among emergency surgical ICU patients.