This review is a critical appraisal of the current data comparing restrictive vs. liberal transfusion strategies for patients who are critically ill in ICUs. We focus on four subsets of critically ill patients: pediatric patients, patients with gastrointestinal bleeds, septic patients and patients undergoing cardiac surgery.
Almost a decade after the TRICC trial, a randomized trial showing the safety of a restrictive transfusion threshold in critically ill patients, four large randomized controlled trials have shown that a restrictive transfusion strategy is safe in pediatric critically ill patients, patients with acute upper gastrointestinal bleeds, patients with septic shock and patients undergoing cardiac surgery. A large multicenter randomized trial is underway to determine the safety of a restrictive strategy in myocardial infarction.
A restrictive transfusion threshold is recommended in nearly all critically ill patients. This is at least noninferior to more liberal transfusion practice; in addition, a restrictive threshold has shown improved outcomes in some patients and decreased chances of adverse events in patients. Judicious use of red cells improves patient outcome and protects the blood supply, a limited resource. More data are needed to determine appropriate transfusion threshold recommendations for patients with traumatic brain injury and acute coronary syndrome.
aHarvard Medical School, Beth Israel Deaconess Medical Center Internal Medicine Residency, Carl J. Shapiro Institute for Education and Research, Division of Pulmonary, Critical Care, and Sleep Medicine, Medical Intensive Care Unit
bHarvard Medical School, Laboratory and Transfusion Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
Correspondence to Margaret M. Hayes, Assistant Professor of Medicine, Harvard Medical School, Associate Program Director, Beth Israel Deaconess Medical Center Internal Medicine Residency, Director for External Education, Carl J. Shapiro Institute for Education and Research, Assistant Director, Division of Pulmonary, Critical Care, and Sleep Medicine, Medical Intensive Care Unit, Beth Israel Deaconess Medical Center, East Campus, ES 200, 330 Brookline Avenue, Boston, MA 02215, USA. Tel: +1 617 667 9120; e-mail: Mhayes7@bidmc.harvard.edu