Impact of non-dialysis chronic kidney disease on survival in patients with septic shock

Background: Chronic kidney disease (CKD) is known to expose the patient to a high risk of death due to cardiovascular and infective causes. In parallel, septic shock is a major challenge for cardiovascular and immune system. Therefore we tried to determine whether non-dialysis CKD, defined as a baseline estimated glomerular filtration rate (eGFR) <60ml/min/1.73m(2), for three months prior to the onset of septic shock is an independent risk factor for death. Methods: All patients treated in a teaching hospital medical ICU for septic shock between January 2007 and December 2009 were retrospectively analyzed. Patients in whom baseline eGFR could not be determined (n=14) or patients treated by chronic dialysis (n=21) or kidney transplantation (n=14) were excluded. A total of 163 patients were included. The population was divided according to baseline eGFR >= 60ml/min/1.73m(2) (non-CKD group, n=107) and < 60ml/min/1.73m(2) (CKD group, n=56). Twenty-eight-day and 1-year survival curves were plotted. Prognostic factors were determined using Cox proportional hazards models. Results: Baseline eGFR was significantly higher in the non-CKD group than in the CKD group (81 (67-108) vs. 36 (28-44) ml/min/1.73m(2), respectively; p=0.001). Age, SAPS II, serum creatinine on admission and the number of patients with a history of diabetes, hypertension, heart failure, peripheral artery disease, coronary artery disease and statin medication were significantly higher in the CKD group than in the non-CKD group. The mortality rate was lower in the non-CKD group than in the CKD group after 28 days (50% vs. 70%, respectively; p=0.03) and 1 year (64% vs. 82%, respectively; p=0.03). On multivariate analysis, the dichotomous variable CKD (eGFR < 60ml/min/1.73m(2)) remained significantly associated with the 28-day and 1-year mortality. Conclusions: Non-dialysis CKD appears to be an independent risk factor for death after septic shock.