Acute Kidney Injury after Pediatric Cardiac Surgery: Risk Factors and Outcomes. Proposal for a Predictive Model

Objectives: To characterize the epidemiology and risk factors for acute kidney injury (AKI) after pediatric cardiac surgery in our center, to determine its association with poor short-term outcomes, and to develop a logistic regression model that will predict the risk of AKI for the study population. Methods: This single-center, retrospective study included consecutive pediatric patients with congenital heart disease who underwent cardiac surgery between January 2010 and December 2012. Exclusion criteria were a history of renal disease, dialysis or renal transplantation. Results: Of the 325 patients included, median age three years (1 day---18 years), AKI occurred in 40 (12.3%) on the first postoperative day. Overall mortality was 13 (4%), nine of whom were in the AKI group. AKI was significantly associated with length of intensive care unit stay, length of mechanical ventilation and in-hospital death (p<0.01). Patients’ age and postoperative serum creatinine, blood urea nitrogen and lactate levels were included in the logistic regression model as predictor variables. The model accurately predicted AKI in this population, with a maximum combined sensitivity of 82.1% and specificity of 75.4%. Conclusions: AKI is common and is associated with poor short-term outcomes in this setting. Younger age and higher postoperative serum creatinine, blood urea nitrogen and lactate levels were powerful predictors of renal injury in this population. The proposed model could be a useful tool for risk stratification of these patients.

Nursing Home-Acquired Pneumonia Presenting at the Emergency Department

Nursing home-acquired pneumonia (NHAP) is one of the most common infections arising amongst nursing home residents, and its incidence is expected to increase as population ages. The NHAP recommendation for empiric broad-spectrum antibiotic therapy, arising from the concept of healthcare-associated pneumonia, has been challenged by recent studies reporting low rates of multidrug-resistant (MDR) bacteria. This single center study analyzes the results of NHAP patients admitted through the Emergency Department (ED) at a tertiary center during the year 2010. There were 116 cases, male gender corresponded to 34.5 % of patients and median age was 84 years old (IQR 77-90). Comorbidities were present in 69.8 % of cases and 48.3 % of patients had used healthcare services during the previous 90 days. In-hospital mortality rate was 46.6 % and median length-of-stay was 9 days. Severity assessment at the Emergency Department provided CURB65 index score and respective mortality (%) results: zero: n = 0; one: n = 7 (0 %); two: n = 18 (38.9 %); three: n = 26 (38.5 %); four: n = 30 (53.3 %); and five; n = 22 (68.2 %); and sepsis n = 50 (34.0 %), severe sepsis n = 43 (48.8 %) and septic shock n = 22 (72.7 %). Significant risk factors for in-hospital mortality in multivariate analysis were polypnea (p = 0.001), age ≥ 75 years (p = 0.02), and severe sepsis or shock (p = 0.03) at the ED. Microbiological testing in 78.4 % of cases was positive in 15.4 % (n = 15): methicillin-resistant Staphylococcus aureus (26.7 %), Pseudomonas aeruginosa (20.0 %), S. pneumoniae (13.3 %), Escherichia coli (13.3 %), others (26.7 %); the rate of MDR bacteria was 53.3 %. This study reveals high rates of mortality and MDR bacteria among NHAP hospital admissions supporting the use of empirical broad-spectrum antibiotic therapy in these patients.