Size matters: effect of number of transfusions on adverse renal and clinical events in patients with aki

Abstract Background and Aims AKI and anemia independently worsen the prognosis of hospitalized patients, but their association and adverse effects have been slightly studied. We aimed to investigate the effect of transfusions during hospitalization on hard renal and clinical outcomes of patients with AKI. In addition, we tested the influence of the number of transfusions on mortality between pure AKI (pAKI) and AKI-on-CKD (AoCKD) patients. Method Retrospective cohorts’ study, of in-patients with AKI attended by nephrology during a 12-month period. AKI severity was categorized by KDIGO-2012 criteria; we searched in a Hematology administrative data base for transfusions (and their number) during the hospitalization period. We analyzed epidemiological and clinical variables and compared the rates of the hard outcomes Length of Stay (LoS), Acute Hemodialysis (aHD), Dialysis Dependence at Discharge (DDD), and in-hospital Mortality (IHM) between individuals that didn't and received transfusions. Results We included 275 individuals, 134 (49%) were transfused; they were older and suffered more DM; with no differences in the ICU hospitalization and Charlson's Index. See Table 1A. We observed that transfused patients were classified more frequently in AKI Stage-3, had longer LoS, aHD, were more frequently dialysis dependent and their mortality rate was higher. See Table 1B. We compared patients with less or more than 5 transfusions; the latter group showed a higher rate of adverse events than the group of ≤4 transfusions. See table 1C. Figure 1 plots the K-M curve for survival between pAKI and AoCKD groups showing an excess mortality associated with the number of transfusions, especially in the AoCKD individuals. Conclusion In our study, we found that patients that received transfusions showed worst clinical and renal results including more severe AKI, longer hospital stay, higher rate of acute HD, dialysis dependence at discharge and mortality. We observed that the appearance of these adverse events was associated in a dose dependent manner with the number of transfusions; for these reasons, we consider that number of transfusions should be included in AKI risk models and calculators. Could optimizing the number of transfusions improve the rate of adverse renal and clinical events? We will need prospective and well-powered studies in order to answer this question and to deepen on the issue of AoCKD and worst clinical outcomes if transfused.