title: Restrictive versus liberal transfusion strategy for red blood cell transfusion in critically ill patients and in patients with acute coronary syndrome: a systematic review, meta-analysis and trial sequential analysis.
abstract: The risks and benefits of transfusing critically ill patients continue to evoke controversy. Specifically, the critically ill patients with active ischemic cardiac disease continue to represent a "gray area" in the literature.
  
  
  
  Meta-analysis of the effects of lower versus higher hemoglobin thresholds on mortality in critically ill patients was carried out using PRISMA methodology. A systematic research was performed in PubMed, Embase, and the Cochrane Library (last update, December 2014).
  
  
  
  Anemic critically ill adult patients admitted to intensive care units and/or anemic patients with acute coronary syndrome in which a restrictive vs. liberal transfusion therapy was compared.
  
  
  
  mortality. Included studies were subjected to quantifiable analysis, predefined subgroup analysis, trial sequential analysis and predefined sensitivity analysis.
  
  
  
  Thirty RCT's were initially identified; 6 fulfilled the inclusion criteria, including 2156. There were no differences in mortality between the restrictive and liberal groups (RR: 0.86, 95% CI 0.70-1.05 P=0.14), neither in patients with chronic cardiovascular disease subgroup (RR: 1.13, 95% IC 0.88-1.46 P=0.34). However, there is a trend towards decreased mortality in the subgroup critically ill (RR: 0.86, 95% CI 0.73-1.01 P=0.06); while in the subgroup of patients with acute myocardial infarct seems like it might be a non-significant trend towards increased mortality (RR: 3.85, 95% CI 0.82-18.0 P=0.09).
  
  
  
  Restrictive strategy is at least as effective to liberal strategy in critically ill patients. Nevertheless, there is insufficient evidence to recommend a restrictive strategy for patients with acute coronary syndrome.
authors.affiliation: Department of Anesthesia, Complutense University of Madrid, Hospital Universitario Infanta Leonor, Madrid, Spain - ripo542@gmail.com.
authors.forename: Javier
authors.initials: J
authors.lastname: Ripollés Melchor
authors.forename: Rubén
authors.initials: R
authors.lastname: Casans Francés
authors.forename: Ángel
authors.initials: Á
authors.lastname: Espinosa
authors.forename: Eugenio
authors.initials: E
authors.lastname: Martínez Hurtado
authors.forename: Rosalía
authors.initials: R
authors.lastname: Navarro Pérez
authors.forename: Alfredo
authors.initials: A
authors.lastname: Abad Gurumeta
authors.forename: Misericordia
authors.initials: M
authors.lastname: Basora
authors.forename: José M
authors.initials: JM
authors.lastname: Calvo Vecino
mesh_terms: D054058:Acute Coronary Syndrome / Q000401:mortality / Q000628:therapy*; D000740:Anemia / Q000401:mortality / Q000628:therapy*; D016638:Critical Illness; D017707:Erythrocyte Transfusion / Q000401:mortality; D006454:Hemoglobins; D006801:Humans; D016032:Randomized Controlled Trials as Topic
chemical_list: D006454:Hemoglobins