To transfuse or not transfuse: an intensive appraisal of red blood cell transfusions in the ICU.

PURPOSE OF REVIEW: 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. RECENT FINDINGS: 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. SUMMARY: 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.