1.
Length of red blood cell storage and clinical outcomes in transfused critical ill adults – the Age of Blood Evaluation (ABLE) randomised controlled trial
Lacroix L, Hebert PC, Fergusson DA, Tinmouth A, Cook DJ, Marshall, JC, Clayton L, McIntyre L, Callum J, et al
Transfusion Medicine. 2015;25((Suppl. 1)):6.. Abstract No. S10
2.
Age of transfused blood in critically ill adults
Lacroix J, Hebert PC, Fergusson DA, Tinmouth A, Cook DJ, Marshall JC, Clayton L, McIntyre L, Callum J, Turgeon AF, et al
New England Journal of Medicine. 2015;372((15):):1410-8.
Abstract
BACKGROUND Fresh red cells may improve outcomes in critically ill patients by enhancing oxygen delivery while minimizing the risks of toxic effects from cellular changes and the accumulation of bioactive materials in blood components during prolonged storage. METHODS In this multicenter, randomized, blinded trial, we assigned critically ill adults to receive either red cells that had been stored for less than 8 days or standard-issue red cells (the oldest compatible units available in the blood bank). The primary outcome measure was 90-day mortality. RESULTS Between March 2009 and May 2014, at 64 centers in Canada and Europe, 1211 patients were assigned to receive fresh red cells (fresh-blood group) and 1219 patients were assigned to receive standard-issue red cells (standard-blood group). Red cells were stored a mean (+/-SD) of 6.1+/-4.9 days in the fresh-blood group as compared with 22.0+/-8.4 days in the standard-blood group (P<0.001). At 90 days, 448 patients (37.0%) in the fresh-blood group and 430 patients (35.3%) in the standard-blood group had died (absolute risk difference, 1.7 percentage points; 95% confidence interval [CI], -2.1 to 5.5). In the survival analysis, the hazard ratio for death in the fresh-blood group, as compared with the standard-blood group, was 1.1 (95% CI, 0.9 to 1.2; P=0.38). There were no significant between-group differences in any of the secondary outcomes (major illnesses; duration of respiratory, hemodynamic, or renal support; length of stay in the hospital; and transfusion reactions) or in the subgroup analyses. CONCLUSIONS Transfusion of fresh red cells, as compared with standard-issue red cells, did not decrease the 90-day mortality among critically ill adults. (Funded by the Canadian Institutes of Health Research and others; Current Controlled Trials number, ISRCTN44878718.).
3.
Do blood transfusions improve outcomes related to mechanical ventilation?
Hebert PC, Blajchman MA, Cook DJ, Yetisir E, Wells G, Marshall J, Schweitzer I, Transfusion Requirements in Critical Care Investigators for the Canadian Critical Care Trials Group
Chest. 2001;119((6):):1850-7.
Abstract
BACKGROUND Correcting the decrease in oxygen delivery from anemia using allogeneic RBC transfusions has been hypothesized to help with increased oxygen demands during weaning from mechanical ventilation. However, it is also possible that transfusions hinder the process because RBCs may not be able to adequately increase oxygen delivery. In this study, we determined whether a liberal RBC transfusion strategy improved outcomes related to mechanical ventilation. METHODS Seven hundred thirteen patients receiving mechanical ventilation, representing a subgroup of patients from a larger trial, were randomized to either a restrictive transfusion strategy, receiving allogeneic RBC transfusions at a hemoglobin concentration of 7.0 g/dL (and maintained between 7.0 g/dL and to 9.0 g/dL), or to a liberal transfusion strategy, receiving RBCs at 10.0 g/dL (and maintained between 10.0 g/dL and 12.0 g/dL). The larger trial was designed to evaluate transfusion practice rather than weaning per se. RESULTS Baseline characteristics in the restrictive-strategy group (n = 357) and the liberal-strategy group (n = 356) were comparable. The average durations of mechanical ventilation were 8.3 +/- 8.1 days and 8.3 +/- 8.1 days (95% confidence interval [CI] around difference, - 0.79 to 1.68; p = 0.48), while ventilator-free days were 17.5 +/- 10.9 days and 16.1 +/- 11.4 days (95% CI around difference, - 3.07 to 0.21; p = 0.09) in the restrictive-strategy group vs the liberal-strategy group, respectively. Eighty-two percent of the patients in the restrictive-strategy group were considered successfully weaned and extubated for at least 24 h, compared to 78% for the liberal-strategy group (p = 0.19). The relative risk (RR) of extubation success in the restrictive-strategy group compared to the liberal-strategy group, adjusted for the confounding effects of age, APACHE (acute physiology and chronic health evaluation) II score, and comorbid illness, was 1.07 (95% CI, 0.96 to 1.26; p = 0.43). The adjusted RR of extubation success associated with restrictive transfusion in the 219 patients who received mechanical ventilation for > 7 days was 1.1 (95% CI, 0.84 to 1.45; p = 0.47). CONCLUSION In this study, there was no evidence that a liberal RBC transfusion strategy decreased the duration of mechanical ventilation in a heterogeneous population of critically ill patients.