title: Epidemiology of RBC Transfusions in Patients With Severe Acute Kidney Injury: Analysis From the Randomized Evaluation of Normal Versus Augmented Level Study.
abstract: OBJECTIVE
  To assess the epidemiology and outcomes associated with RBC transfusion in patients with severe acute kidney injury requiring continuous renal replacement therapy.
  
  
  METHODS
  Post hoc analysis of data from a multicenter, randomized, controlled trial.
  
  
  METHODS
  Thirty-five ICUs in Australia and New Zealand.
  
  
  METHODS
  Cohort of 1,465 patients enrolled in the Randomized Evaluation of Normal versus Augmented Level replacement therapy study.
  
  
  METHODS
  Daily information on morning hemoglobin level and amount of RBC transfused were prospectively collected in the Randomized Evaluation of Normal versus Augmented Level study. We analyzed the epidemiology of such transfusions and their association with clinical outcomes.
  
  
  RESULTS
  Overall, 977 patients(66.7%) received a total of 1,192 RBC units. By day 5, 785 of 977 transfused patients (80.4%) had received at least one RBC transfusion. Hemoglobin at randomization was lower in transfused than in nontransfused patients (94 vs 111 g/L; p < 0.001). Mean daily hemoglobin was 88 ± 7 and 99 ± 12 g/L in transfused and nontransfused patients. Among transfused patients, 228 (46.7%) had died by day 90 when compared with 426 (43.6%) of nontransfused patients (p = 0.27). Survivors received on average 316 ± 261 mL of RBC, whereas nonsurvivors received 302 ± 362 mL (p = 0.42). On multivariate Cox regression analysis, RBC transfusion was independently associated with lower 90-day mortality (hazard ratio, 0.55; 95% CI, 0.38-0.79). However, we found no independent association between RBC transfusions and mortality when the analyses were restricted to patients surviving at least 5 days (hazard ratio, 1.29; 95% CI, 0.90-1.85). We found no independent association between RBC transfusion and renal replacement therapy-free days, mechanical ventilator-free days, or length of stay in ICU or hospital.
  
  
  CONCLUSIONS
  In patients with severe acute kidney injury treated with continuous renal replacement therapy, we found no association of RBC transfusion with 90-day mortality or other patient-centered outcomes. The optimal hemoglobin threshold for RBC transfusion in such patients needs to be determined in future randomized controlled trials.
authors.affiliation: 1Australian and New Zealand Intensive Care Research Centre (ANZIC-RC), Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia. 2Department of Intensive Care, Austin Hospital, Melbourne, VIC, Australia. 3Section of Anaesthesia and Intensive Care Medicine, Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden. 4Department of Anaesthesiology, Helsinki University Central Hospital, Helsinki, Finland. 5Department of Nephrology, The George Institute for Global Health, University of Sydney, Sydney, Australia.
authors.forename: Rinaldo
authors.initials: R
authors.lastname: Bellomo
authors.forename: Johan
authors.initials: J
authors.lastname: Mårtensson
authors.forename: Kirsi-Maija
authors.initials: KM
authors.lastname: Kaukonen
authors.forename: Serigne
authors.initials: S
authors.lastname: Lo
authors.forename: Martin
authors.initials: M
authors.lastname: Gallagher
authors.forename: Alan
authors.initials: A
authors.lastname: Cass
authors.forename: John
authors.initials: J
authors.lastname: Myburgh
authors.forename: Simon
authors.initials: S
authors.lastname: Finfer
mesh_terms: D058186:Acute Kidney Injury / Q000401:mortality / Q000628:therapy*; D000368:Aged; D000369:Aged, 80 and over; D016638:Critical Illness / Q000628:therapy*; D017707:Erythrocyte Transfusion / Q000379:methods* / Q000401:mortality; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012044:Regression Analysis; D017582:Renal Replacement Therapy / Q000379:methods*
chemical_list: D006454:Hemoglobins