Hospital-acquired acute kidney injury in Chinese very elderly persons.

Objectives: To investigate the incidence, pathogenetic factors, the prognosis and correlation factors of the hospitalized very elderly patients(>= 80) with acute kidney injury (AKI). Methods: The clinical data of the patients older than 80 admitted in PLA General Hospital from June 1, 2008 to December 31, 2009 were collected. The patients with AKI were identified and their records of clinical characteristics were analyzed. Results: The overall incidence of AKI in very elderly patients was 14.8%. Infection was the major cause of AKI in those patients. The multifactorial analysis showed that the most common causes of AKI were hypovolemia, nephrotoxic drugs, cardiac dysfunction and respiratory failure. Antibiotics were the most common factor in nephrotoxic drugs. Comparing with de novo AKI, the patients with Acute-on-Chronic AKI were older, the percent complication of multiple organ dysfunction syndrome (MODS), hyperlipidemia and the rate of recurring AKI was higher. Cox proportional hazard models showed variables of MODS, heart failure and gastrointestinal bleeding were independent risk factors for 90 days end outpoint, and MODS, malnutrition, gastrointestinal bleeding and absolute increase in SCR were independent risk factors for one year survival, the use of alpha-ketoacid was showed to be a protective factor(odd ratio=0.656). Conclusion: The incidence of AKI in the very elderly hospitalized patients was high. Infections, hypovolemia, nephrotoxic drugs and cardiovascular diseases were among the common causes. Active treatment of primary diseases, avoidance of complications and use of alpha-ketoacid were beneficial for improving the prognosis of the very elderly patients with AKI.