title: Clinical Practice Guidelines From the AABB: Red Blood Cell Transfusion Thresholds and Storage.
abstract: More than 100 million units of blood are collected worldwide each year, yet the indication for red blood cell (RBC) transfusion and the optimal length of RBC storage prior to transfusion are uncertain.
  
  
  
  To provide recommendations for the target hemoglobin level for RBC transfusion among hospitalized adult patients who are hemodynamically stable and the length of time RBCs should be stored prior to transfusion.
  
  
  
  Reference librarians conducted a literature search for randomized clinical trials (RCTs) evaluating hemoglobin thresholds for RBC transfusion (1950-May 2016) and RBC storage duration (1948-May 2016) without language restrictions. The results were summarized using the Grading of Recommendations Assessment, Development and Evaluation method. For RBC transfusion thresholds, 31 RCTs included 12 587 participants and compared restrictive thresholds (transfusion not indicated until the hemoglobin level is 7-8 g/dL) with liberal thresholds (transfusion not indicated until the hemoglobin level is 9-10 g/dL). The summary estimates across trials demonstrated that restrictive RBC transfusion thresholds were not associated with higher rates of adverse clinical outcomes, including 30-day mortality, myocardial infarction, cerebrovascular accident, rebleeding, pneumonia, or thromboembolism. For RBC storage duration, 13 RCTs included 5515 participants randomly allocated to receive fresher blood or standard-issue blood. These RCTs demonstrated that fresher blood did not improve clinical outcomes.
  
  
  
  It is good practice to consider the hemoglobin level, the overall clinical context, patient preferences, and alternative therapies when making transfusion decisions regarding an individual patient. Recommendation 1: a restrictive RBC transfusion threshold in which the transfusion is not indicated until the hemoglobin level is 7 g/dL is recommended for hospitalized adult patients who are hemodynamically stable, including critically ill patients, rather than when the hemoglobin level is 10 g/dL (strong recommendation, moderate quality evidence). A restrictive RBC transfusion threshold of 8 g/dL is recommended for patients undergoing orthopedic surgery, cardiac surgery, and those with preexisting cardiovascular disease (strong recommendation, moderate quality evidence). The restrictive transfusion threshold of 7 g/dL is likely comparable with 8 g/dL, but RCT evidence is not available for all patient categories. These recommendations do not apply to patients with acute coronary syndrome, severe thrombocytopenia (patients treated for hematological or oncological reasons who are at risk of bleeding), and chronic transfusion-dependent anemia (not recommended due to insufficient evidence). Recommendation 2: patients, including neonates, should receive RBC units selected at any point within their licensed dating period (standard issue) rather than limiting patients to transfusion of only fresh (storage length: <10 days) RBC units (strong recommendation, moderate quality evidence).
  
  
  
  Research in RBC transfusion medicine has significantly advanced the science in recent years and provides high-quality evidence to inform guidelines. A restrictive transfusion threshold is safe in most clinical settings and the current blood banking practices of using standard-issue blood should be continued.
authors.affiliation: Division of General Internal Medicine, Rutgers Robert Wood Johnson Medical School, Rutgers University, New Brunswick, New Jersey.
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Carson
authors.affiliation: Department of Clinical Epidemiology and Biostatistics and Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Gordon
authors.initials: G
authors.lastname: Guyatt
authors.affiliation: Department of Medicine, McMaster University, Hamilton, Ontario, Canada.
authors.forename: Nancy M
authors.initials: NM
authors.lastname: Heddle
authors.affiliation: Department of Pathology and Immunology, Washington University School of Medicine, St Louis, Missouri.
authors.forename: Brenda J
authors.initials: BJ
authors.lastname: Grossman
authors.affiliation: Department of Laboratory Medicine and Pathology, University of Minnesota Medical School, Minneapolis.
authors.forename: Claudia S
authors.initials: CS
authors.lastname: Cohn
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Vermont Medical Center, Burlington.
authors.forename: Mark K
authors.initials: MK
authors.lastname: Fung
authors.affiliation: Division of Hematology, University of Washington, Seattle.
authors.forename: Terry
authors.initials: T
authors.lastname: Gernsheimer
authors.affiliation: Department of Surgery, University of Texas Medical School, Galveston.
authors.forename: John B
authors.initials: JB
authors.lastname: Holcomb
authors.affiliation: Department of Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia.
authors.forename: Lewis J
authors.initials: LJ
authors.lastname: Kaplan
authors.affiliation: America's Blood Centers, Washington, DC11Department of Medicine, Division of Infectious Diseases, Carver College of Medicine, University of Iowa, Iowa City.
authors.forename: Louis M
authors.initials: LM
authors.lastname: Katz
authors.affiliation: Glenn Dale, Maryland.
authors.forename: Nikki
authors.initials: N
authors.lastname: Peterson
authors.affiliation: Department of Pathology, Feinberg School of Medicine, Northwestern University, Evanston, Illinois.
authors.forename: Glenn
authors.initials: G
authors.lastname: Ramsey
authors.affiliation: Division of Cardiology, Duke University Medical Center, Durham, North Carolina.
authors.forename: Sunil V
authors.initials: SV
authors.lastname: Rao
authors.affiliation: Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia.
authors.forename: John D
authors.initials: JD
authors.lastname: Roback
authors.affiliation: Departments of Anesthesiology, Critical Care Medicine, Pain Management, and Hyperbaric Medicine, Englewood Hospital and Medical Center, Englewood, New Jersey.
authors.forename: Aryeh
authors.initials: A
authors.lastname: Shander
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Aaron A R
authors.initials: AA
authors.lastname: Tobian
mesh_terms: D001771:Blood Banks / Q000592:standards*; D016638:Critical Illness; D003657:Decision Making; D017707:Erythrocyte Transfusion / Q000379:methods / Q000592:standards*; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D057240:Patient Preference; D012016:Reference Values; D013997:Time Factors
chemical_list: D006454:Hemoglobins