Predictors and outcome of ICU-readmission after cardiac surgery

Objectives: Readmission to intensive care unit (ICU) after cardiac surgery is associated with higher costs and may be correlated with an increased mortality. We wanted to evaluate predictors of ICU readmission and to analyze the outcome of those patients. Methods: 3523 patients who underwent CABG- and/or valve surgery were reviewed retrospectively. The reasons for readmission and the postoperative course were analyzed. Results: Of the 3374 patients discharged from the ICU, 5.9% of patients required a second intensive care (group r). Readmission rate was 4.8% following CABG and 8.9% following valve±CABG (p<0.05). The mean interval from ICU discharge to readmission was 3.3±6.2 days. Among the patients who were not readmitted 1.3% died in hospital, compared to 14.4% in gr. r (p<0.05). After readmission, the mean length of stay on ICU and in hospital was 7.1±5.9 and 21.3±11.1 days (3.1±1.2 and 13.1±5.1 days in other patients (p<0.05)). Main reasons for readmission were respiratory failure (59%), cardiovascular instability (25%), renal failure (6.5%), cardiac tamponade/bleeding (6%), gastrointestinal complications (2%) and sepsis (1.5%). Multivariate logistic regression analysis revealed that preoperative renal failure, mechanical ventilation >24h, re-exploration for bleeeding and low cardiac output state were independent predictors for readmission. Conclusion: Patients after valve surgery are more likely to require readmission to ICU. Respiratory complications were the most common reasons for readmission. To reduce the readmission rate, it is necessary to treat cardio-respiratory problems early, particularly in patients showing predictive risk factors.