title: Liberal transfusion strategy improves survival in perioperative but not in critically ill patients. A meta-analysis of randomised trials.
abstract: BACKGROUND
  Guidelines support the use of a restrictive strategy in blood transfusion management in a variety of clinical settings. However, recent randomized controlled trials (RCTs) performed in the perioperative setting suggest a beneficial effect on survival of a liberal strategy. We aimed to assess the effect of liberal and restrictive blood transfusion strategies on mortality in perioperative and critically ill adult patients through a meta-analysis of RCTs.
  
  
  METHODS
  We searched PubMed/Medline, Embase, Cochrane Central Register of Controlled Trials, Transfusion Evidence Library, and Google Scholar up to 27 March 2015, for RCTs performed in perioperative or critically ill adult patients, receiving a restrictive or liberal transfusion strategy, and reporting all-cause mortality. We used a fixed or random-effects model to calculate the odds ratio (OR) and 95% confidence interval (CI) for pooled data. We assessed heterogeneity using Cochrane's Q and I(2) tests. The primary outcome was all-cause mortality within 90-day follow-up.
  
  
  RESULTS
  Patients in the perioperative period receiving a liberal transfusion strategy had lower all-cause mortality when compared with patients allocated to receive a restrictive transfusion strategy (OR 0.81; 95% CI 0.66‒1.00; P=0.05; I(2)=25%; Number needed to treat=97) with 7552 patients randomized in 17 trials. There was no difference in mortality among critically ill patients receiving a liberal transfusion strategy when compared with the restrictive transfusion strategy (OR 1.10; 95% CI 0.99‒1.23; P=0.07; I(2)=34%) with 3469 patients randomized in 10 trials.
  
  
  CONCLUSIONS
  According to randomized published evidence, perioperative adult patients have an improved survival when receiving a liberal blood transfusion strategy.
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, Milan 20132, Italy Academician EN Meshalkin Novosibirsk State Budget Research Institute of Circulation Pathology, Novosibirsk, Russia.
authors.forename: E
authors.initials: E
authors.lastname: Fominskiy
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, Milan 20132, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Putzu
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, Milan 20132, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Monaco
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, Milan 20132, Italy.
authors.forename: A M
authors.initials: AM
authors.lastname: Scandroglio
authors.affiliation: Academician EN Meshalkin Novosibirsk State Budget Research Institute of Circulation Pathology, Novosibirsk, Russia.
authors.forename: A
authors.initials: A
authors.lastname: Karaskov
authors.affiliation: Surgical Intensive Care Unit and Department of Anaesthesiology, Heart Institute (InCor), Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: F R B G
authors.initials: FR
authors.lastname: Galas
authors.affiliation: Surgical Intensive Care Unit and Department of Anaesthesiology, Heart Institute (InCor), Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
authors.forename: L A
authors.initials: LA
authors.lastname: Hajjar
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, Milan 20132, Italy Vita-Salute San Raffaele University of Milan, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Zangrillo
authors.affiliation: Department of Anaesthesia and Intensive Care, IRCCS San Raffaele Scientific Institute, Via Olgettina 60, Milan 20132, Italy Vita-Salute San Raffaele University of Milan, Italy landoni.giovanni@hsr.it.
authors.forename: G
authors.initials: G
authors.lastname: Landoni
mesh_terms: D001803:Blood Transfusion / Q000706:statistics & numerical data*; D003422:Critical Care / Q000379:methods* / Q000706:statistics & numerical data; D016638:Critical Illness / Q000401:mortality*; D006801:Humans; D019990:Perioperative Care / Q000379:methods* / Q000401:mortality* / Q000706:statistics & numerical data; D016032:Randomized Controlled Trials as Topic; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: anesthesia; blood transfusion; critical illness; mortality; perioperative care