Acute kidney injury and mild therapeutic hypothermia in patients after cardiopulmonary resuscitation - a post hoc analysis of a prospective observational trial

Abstract

Background: The aim of this study was to investigate the influence of mild therapeutic hypothermia (MTH) on the incidence of and recovery from acute kidney injury (AKI). Methods: Patients who had undergone successful cardiopulmonary resuscitation (CPR) were included. Serum creatinine and cystatin C were measured at baseline, daily up to 5days and at ICU discharge. AKI was defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria. MTH was applied for 24h targeting a temperature of 33°C. Neurological outcome was assessed with the Cerebral Performance Categories score at hospital discharge. Results: 126 patients were included in the study; 73 patients (58%) developed AKI. Patients treated with MTH had a significantly lower incidence of AKI as compared to normothermia (NT) (44 vs. 69%; p=0.004). Patients with less favourable neurological outcomes had a significantly higher rate of AKI, although when treated with MTH the occurrence of AKI was reduced (50 vs. 80%; p=0.017). Furthermore, MTH treatment was accompanied by significantly lower creatinine levels on day 0-1 and at ICU discharge (day 0: 1.12 (0.90-1.29) vs. 1.29 (1.00-1.52) mg/dl; p=0.016) and lower cystatin C levels on day 0-3 and at ICU discharge (day 0: 0.88 (0.77-1.10) vs. 1.29 (1.06-2.16) mg/l; p<0.001). Conclusions: Mild therapeutic hypothermia seems to have a protective effect against the development of AKI and on renal recovery. This may be less pronounced in patients with a favourable neurological outcome.