Purpose: The purpose of the present study was to investigate the association between the perioperative neutrophil to lymphocyte ratio (NLR) and cardiac surgery patient outcomes. Patients and methods: A retrospective cohort study of 145 patients who underwent cardiac surgery in a tertiary hospital of Athens, Greece, from January to March 2015, was conducted. By using a structured short questionnaire, this study reviewed the electronic hospital database and the medical and nursing patient records for data collection purposes. The statistical significance was two-tailed, and p-values <0.05 were considered significant. The statistical analysis was performed with Mann–Whitney U test and Spearman’s correlation coefficient, by using the Statistical Package for Social Sciences software (IBM SPSS 21.0 for Windows). Results: The increased preoperative levels of NLR were associated with significantly higher mortality, both in-hospital (p=0.001) and 30-day (p=0.002), prolonged postoperative hospital length of stay (LOS), both in the cardiac intensive care unit (ICU) (p=0.002), and in-hospital (p=0.018), and likewise with delayed tracheal extubation (p≤0.001). Furthermore, patients with elevated NLR during the second postoperative day had significantly higher in-hospital mortality (p=0.018), increased incidence of pneumonia (p=0.022), higher probability of readmission to the ICU (p=0.002), prolonged ICU LOS (p≤0.001), and delayed tracheal extubation (p≤0.001). Conclusion: Increased perioperative NLR seems to be associated with significantly higher mortality and morbidity in cardiac surgery patients. At the same time, NLR is a significant and inexpensive biomarker for the early identification of patients at high risk for complications. In addition, NLR levels could lead clinicians to perform measures for the optimal therapeutic patient approach.

Introduction: Readmission in the intensive care unit (ICU) is a significant morbidity index, which has been related to poor patient outcomes Aim: To identify the preoperative and intraoperative risk factors for readmission in the cardiac surgery ICU. Methods: We conducted a retrospective cohort study of 595 consecutive patients who were admitted to the cardiac surgery ICU of a tertiary hospital of Athens - Greece during the one-year period (September 2011-September 2012). Data collection was carried out, retrospectively, by the use of a short questionnaire and based on the review of medical and nursing patient records at December 2012. Results: The incidence of ICU readmission was 3.7% (22/595). Respiratory disorders were the main reason for readmission (45.4%). Readmitted patients had a significantly higher in-hospital mortality compared to those requiring no readmission (P < 0.001). Multivariate analysis revealed that female gender [for males odds ratio (OR) 0.37, 95% confidence interval (CI) 0.15-0.89], high logistic EuroSCORE (OR 1.02, 95% CI 1.00-1.04), prolonged cardiopulmonary (CPB) duration (OR 1.01, 95% CI 1.00-1.02) and preoperative renal failure (OR 1.02, 95% CI 1.00-1.05) were the independent risk factors for readmission to the cardiac surgery ICU. Conclusions: One intraoperative and three preoperative variables are associated strongly with higher probability for ICU readmission. Shorter CPB duration could contribute to lower ICU readmission incidence. In addition, the early identification of high risk patients for readmission in the cardiac surgery ICU could encourage both the more efficient healthcare planning and resources allocation.