Abstract:

Objective

To assess the prognosis and risk factors of patients with acute kidney injury (AKI) in intensive care unit (ICU).

Methods

We performed a retrospective study of 862 patients in the ICU of the First Affiliated Hospital of Dalian Medical University from September 2006 to September 2011. AKI were defined by Acute Kidney Injury Network (AKIN) criteria. The clinical data were collected including demography, renal function, urine output, serum potassium, APACHEⅡscore, and continuous renal replacement therapy (CRRT) treatment scheme. Logistic regression and COX regression were used to analyze the risk factors relevant to prognosis and survival of the patients.

Results

26.8%of patients (231/862) developed AKI, the leading cause of which was severe infection (28.5%, 66/231).The all-cause mortality of ICU patients was 48.6% (419/862). The mortality was higher in patients of AKI than in non-AKI patients [71.0% (164/231) vs. 40.4% (255/631)]. Moreover, the mortality increased with primary serum creatinine (Scr), the changes of Scr before and after the treatment, the onset time of AKI,the severity of AKI, the number of organs involved, and the APACHEⅡscore. There were significant improvements in AKI patients after CRRT, including APACHEⅡscore, mean artery pressure (MAP), Scr,blood urea nitrogen, urine output, and serum potassium. But the mortality was irrelevant to whether CRRT was used or not. Logistic analysis showed that hyperkalemia (OR = 4.282, 95%CI = 1.519 - 12.070), high APACHEⅡscore (OR = 1.318，95%CI = 1.192 - 1.457) were the independent risk factors for mortality,while higher MAP was associated with lower mortality (OR = 0.972, 95%CI = 0.946 - 0.999). Cox regression analysis indicated that the number of organs involved and APACHEⅡscore were influencing factors for the survival time of patients, and CRRT was associated with long survival time.

Conclusion

ICU patients had higher incidence and mortality of AKI. Hyperkalemia, higher APACHEⅡscores and lower MAP after treatment were the risk factors for mortality of AKI patients. Though CRRT was not beneficial to AKI, it could improve the survival time of patients during the hospitalization.

Key words: Intensive care unit, Acute kidney injury, Renal replacement therapy, Prognosis