4 Original Article Abstract Objective: To compare a restrictive versus a liberal transfusion strategy in patients with moderate to severe closed head injury following multiple trauma in 13 Canadian intensive care units (ICUs). Methods: This is a subgroup analysis of a multicenter randomized controlled clinical trial involving sixty-seven critically ill patients from the Transfusion Requirements in the Critical Care trial who sustained a closed head injury. Patients had a hemoglobin concentration less than 9.0 g/dL within 72 hours of admission to the ICU. Patients were randomized to a restrictive allogeneic red blood cell transfusion strategy (hemoglobin 7.0 g/dL and maintained between 7.0 and 9.0 g/dL) or a liberal strategy (hemoglobin 10.0 g/dL and maintained between 10.0 and 12.0 g/dL). Results: Baseline characteristics in the restrictive ( n = 29) and the liberal ( n = 38) transfusion groups were comparable. Average hemoglobin concentrations and red blood cell units transfused per patient were significantly lower in the restrictive compared to the liberal group. The 30-day all-cause mortality rates in the restrictive group were 17% as compared to 13% in the liberal group (risk difference 4.1 with 95% confidence interval [CI], 13.4 to 21.5, p = 0.64). Presence of multiple organ dysfunction (12.1 ± 6.4 versus 10.6 ± 6.3, p = 0.35) and changes in multiple organ dysfunction from baseline scores adjusted for death (4.5 ± 6.2 versus 3.4 ± 6.2, p = 0.49) were similar between the restrictive and liberal transfusion groups, respectively. Median length of stay in ICU (10 days, interquartile range 5 to 21 days versus 8 days, interquartile range 5 to 11 days, p = 0.26) and hospital (27 days, interquartile range 14 to 39 days versus 30.5 days, interquartile range 17 to 47 days, p = 0.72) were similar between the restrictive and liberal transfusion groups. Conclusions: We were unable to detect significant improvements in mortality with a liberal as compared to restrictive transfusion strategy in critically ill trauma victims with moderate to severe head injury. Key Words: Critical care; brain injuries; wounds and injuries; erythrocyte transfusion; randomized controlled trial. (Neurocrit. Care 2006;05:4–9) Neurocritical Care Copyright © 2006 Humana Press Inc. All rights of any nature whatsoever are reserved. ISSN 1541-6933/06/5:4–9 ISSN 1556-0961 (Online) DOI: 10.1385/Neurocrit. Care 2006;05:4–9 Effect of a Liberal Versus Restrictive Transfusion Strategy on Mortality in Patients With Moderate to Severe Head Injury Lauralyn A. McIntyre, 1, * Dean A. Fergusson, 1 James S. Hutchison, 2 Giuseppe Pagliarello, 3 John C. Marshall, 4 ElizabethYetisir, 5 Gregory M.T. Hare, 6 Paul C. Hébert, 1 for the Canadian Critical Care Trials Group 1 Centre for Transfusion and Critical Care Research, Clinical Epidemiology Unit, Critical Care Program, University of Ottawa and Ottawa Health Research Institute; 2 Departments of Critical Care and Pediatrics, Hospital for Sick Children, University of Toronto; 3 Critical Care Program, The Ottawa Hospital; 4 Department of Surgery, Critical Care Program, University of Toronto; 5 University of Ottawa Heart Institute, Ottawa; 6 Department of Anesthesia and Physiology, University of Toronto, St. Michael’s Hospital *Correspondence and reprint requests to: Lauralyn A. McIntyre, Centre for Transfusion Research and Clinical Epidemiology Program, Ottawa Health Research Institute, General Campus, 501 Smyth Road, Box 201, Ottawa, Ontario, K1H 8L6. E-mail: lmcintyre@ottawahospital.on.ca