Readmission to the intensive care unit after "fast-track" cardiac surgery: risk factors and outcomes.

Background: The introduction of "fast-track" management into cardiac surgery has significantly shortened the intensive care unit (ICU) length of stay. Readmission to the ICU, traditionally used as a quality index, has not been investigated in these patients. The aim of this study was to assess the causes, risk factors, and outcomes associated with readmission to the ICU.
Methods: All patients undergoing open-heart surgery in a tertiary care, university-affiliated center were included in this prospective observational study. Preoperative and intraoperative data as well as ICU outcome were noted in all patients.
Results: Over the 27-month study period,1,613 patients were targeted for fast track management (discharge from ICU on the first postoperative day). The readmission rate was 3.29% (53 patients). Forty-three percent of readmissions occurred within 24 hours of discharge usually because of pulmonary problems (43%) or arrhythmias (13%). Readmission was associated with a prolonged ICU stay (105 +/- 180.0 versus 19.2 +/- 2.4 hours of initial ICU stay) and worse outcome: the only patients who died (6 of 53, 11.3%) were in this group. On multivariate analysis, a Bernstein-Parsonnet risk estimate more than 20 strongly predicted readmission (odds ratio, 3.08; 95% confidence interval, 1.43 to 6.69).
Conclusions: Among a homogeneous group of patients targeted for fast-track management after cardiac surgery, readmission although uncommon is associated with a longer second ICU stay and significant mortality. The recognition of specific risk factors may allow for appropriate modification of the postoperative course.