Risk factors for acute kidney injury (AKI) among patients in the intensive care unit (ICU) include hypovolemia, use of diuretics, and the presence of chronic kidney disease (CKD) prior to ICU admission, according to a prospective, population-based Finnish study.
The study by Sara Nisula, MD, of Helsinki University, and colleagues included 2,901 patients in 17 ICUs. Of these, 39.3% experienced AKI, which the researchers defined first using the Acute Kidney Injury Network (AKIN) criteria supplemented with a baseline creatinine and second with the Kidney Disease: Improving Global Outcomes (KDIGO) criteria.
The population-based incidence of ICU-treated AKI was 746 per million population per year, which is comparable to previous large multicenter ICU studies, Dr. Nisula’s team reported online in Intensive Care Medicine. Hospital mortality for AKI patients was 25.6%, which is comparable to or lower than in other studies, they observed. The 90-day mortality for AKI patients was 33.7%.
After adjusting for multiple variables, pre-ICU hypovolemia and CKD were independently associated with a 2.2 times and 2.6 times increased risk for AKI. Pre-ICU use of diuretics and colloids were independently associated with a 68% and 35% increased risk.
The investigators noted that their study is the first to evaluate the population-based incidence of ICU-treated AKI using a prospective, multicenter, nationwide study design, and with AKI defined by RIFLE, AKIN, or KDIGO criteria. In addition, no studies of 90-day mortality among ICU-treated AKI patients classified according to RIFLE or AKIN criteria exist.