Critically ill patients readmitted to intensive care units--lessons to learn?

OBJECTIVE: To evaluate risk factors in critically ill patients who were readmitted to an intensive care unit (ICU) during their hospital stay. DESIGN: Prospective multicenter cohort study. PATIENTS AND SETTING: A total of 15180 patients discharged from 30 medical, surgical and mixed ICUs in Austria over a 2-year period. MEASUREMENTS AND RESULTS: The data analyzed included data on patients' clinical characteristics, Simplified Acute Physiology Score II (SAPS II), Logistic Organ Dysfunction system (LOD), Simplified Therapeutic Intervention Scoring System (TISS-28), length of ICU stay, ICU mortality and hospital mortality. Of the 15180 patients who survived the first ICU stay, 780 patients (5.1%) were readmitted. These patients had more than a fourfold risk of dying during their hospital stay (21.7 vs 5.2%, p<0.001). For mechanically ventilated patients, the time between extubation and discharge during the first ICU stay was significantly shorter for readmitted than for non-readmitted patients (median 1 vs 2 days, p<0.001). On the day of their first ICU discharge, readmitted patients were in greater need of organ support, with more patients still requiring ventilatory, cardiovascular and renal support than non-readmitted patients. CONCLUSIONS: The results of this study provide evidence that there exists a group of patients at higher risk of readmission to the ICU. At the time of their first ICU discharge, these patients presented with residual organ dysfunctions, which were associated with an increased risk of being readmitted. Optimizing organ functions in these patients before discharge from the ICU could result in reduced readmission rates.