Is Anemia at Hospital Admission Associated with In-Hospital Acute Kidney Injury Occurrence?

Abstract

Background: The effect of acute kidney injury (AKI) on anemia has been well-documented. However, the effect of ‘preexisting’ anemia on AKI has been less addressed. The aims of the present study were to investigate (1) the association between anemia at hospital admission and AKI occurrence, and (2) the effect of ‘preexisting’ anemia on the clinical outcomes of AKI. Methods: A retrospective cohort study was undertaken among patients aged ≧17 years who were admitted to our hospital during the year 2006 (n = 34,802). Anemia at hospital admission and AKI occurrences were determined using the WHO definition and the RIFLE criteria, respectively. A subgroup of patients with an estimated glomerular filtration rate ≧60 ml/min/1.73 m² was analyzed separately to control for the effect of chronic kidney disease on anemia. Results: The cumulative incidence of AKI was 11.2% in anemic patients at hospital admission, compared to 5.5% in nonanemic subjects. The association between anemia at admission and AKI occurrence remained statistically significant after controlling for potential confounders (odds ratio 1.5, 95% CI 1.4–1.6). In addition, an association between anemia at hospital admission and clinical outcomes of AKI was observed. Conclusion: Anemia at hospital admission should be recognized as a potential risk factor for in-hospital AKI occurrence.

Prognostic value of Red Blood Cell Distribution Width in Acute Kidney Injury Patients: A Systematic Review and Meta-analysis

“…Although the mechanism of the RDW values in patients with AKI is at present unclear, several potential explanations may account for the relationship between RDW and AKI. Among the risk factors, anemia is the independent related to AKI [46], one present study indicated that the elevated RDW group in AKI was found to have low red blood cell (RBC) which may contribute to increase AKI occurring [28]. Previous studies have demonstrated RDW levels are associated with inflammation and serum antioxidants which mediate effects on RDW through IL-6 [47], and the IL-6 levels in serum may predict the mortality of AKI patients [48].…”

Risk Factors for Acute Kidney Injury and In-Hospital Mortality in Patients Receiving Extracorporeal Membrane Oxygenation

“…In this study, patients with an RDW greater than 14.1% showed lower RBC indices than did those with an RDW less than 14.1%. Because anemia is a risk factor for AKI [ 35 ], the low RBC indices found in the elevated RDW group might contribute to increase the odds of stage 3 AKI occurring.…”

From Bad to Worse: Anemia on Admission and Hospital-Acquired Anemia

“…In multiple settings, POA anemia has been associated with increased risk for acute kidney injury, 3 worse outcomes in the setting of stroke, 4 and acute coronary syndromes. 14,15 However, most studies do not report the relative contribution of POA anemia and HAA to patient outcomes.…”