Postoperative anemia is a risk factor for acute kidney injury after open aorta and vena cava surgeries

Open aorta and vena cava surgeries are usually associated with substantial blood loss which may result in postoperative acute kidney injury (AKI). The present study is designed to investigate the prevalence, outcome and risk factors of postoperative AKI associated with open aorta and vena cava surgeries, with a focus on the role of anemia in these conditions. A retrospective review of medical records of Peking Union Medical College Hospital was conducted. Patients who underwent open aorta and vena cava surgeries during January 1, 2010 and June 30, 2014 were included in this study. The primary analysis was between patients underwent open aorta and vena cava surgeryies, with or without postoperative AKI. Multivariable logistic regression models were used to determine risk factors of postoperative AKI. The study included 79 patients (63.3% male) with a mean age of 52.5±17.3 years (range, 17-81 years). Postoperative AKI occurred in 23/79 (29.1%) of the patients. Anemia was present in 11/79 (16%) at baseline, and increased to 45/79 (52%) postoperatively. After adjustment for various risk factors, postoperative anemia (OR, 5.202; 95% CI 1.403-19.285) was independently associated with postoperative AKI. AKI is a common complication in patients who undergo open aorta and vena cava surgeries, and postoperative anemia was the most relevant predictive factor of AKI. Strategies to minimize bleeding and anemia for all patients may be advisable. Further studies are needed to assess the impact of AKI on long term outcome and to examine preventive strategies to address potentially modifiable risk factors.