Restrictive vs liberal transfusion for upper gastrointestinal bleeding: A meta-analysis of randomized controlled trials

Table 1 Characteristics of included studies

Ref.	Design	Regions	Target population	Intervention	Outcome measures
Blair et al[25]	Single center RCT	London, United Kingdom	Acute severe UGIB; no esophageal varices	Early transfusion group (liberal transfusion): at least 2 units of blood No transfusion group (restrictive transfusion): no blood transfusion unless hemoglobin fell below 8 g/dL or they were shocked	Observed results: coagulation results (impedance clotting time, kaolin cephalin clotting time); haematological results (hematocrit); eventual blood transfused; number of rebleed; number of death
Elizalde et al[24]	Single center RCT	Barcelona, Spain	Liver cirrhosis with an acute variceal bleeding episode	PRC group (liberal transfusion): 2 units of packed red cells PPL group (restrictive transfusion): 500 mL of a 5% plasma protein solution	Observed items: hemodynamic measurements (cardiopulmonary pressures, cardiac output, wedged and free hepatic venous pressures, mean arterial blood pressure, systemic vascular resistance); hormonal measurements (plasma renin activity, aldosterone levels, norepinephrine); rheological parameters (plasma volume, blood viscosity)
Villarejo et al[23]	Single center RCT	Buenos Aires, Argentina	Acute digestive hemorrhage with stable haemodynamics	Treatment group (restrictive transfusion): patients underwent normovolemic hemodilution with crystalloid solutions, and the hematocrit value was maintained as ≥ 21% and < 28%; red cell transfusion was given if angina, shock, hemodynamic instability, or hematocrit < 21% Control group (liberal transfusion): the target of transfusion in these patients was the hematocrit value of ≥ 28%	Observed results: organ failure, hospital stay, APACHE II score, red cell transfused, hematocrit, haemoglobin
Villanueva et al[14]	Single center RCT	Barcelona, Spain	Upper gastrointestinal bleeding	Liberal transfusion: the hemoglobin threshold for transfusion was 9 g/dL, with a target range for the post-transfusion hemoglobin level of 9-11 g/dL Restrictive transfusion: the hemoglobin threshold for transfusion was 7 g/dL, with a target range for the post-transfusion hemoglobin level of 7-9 g/dL	Primary endpoints: the rate of death from any cause within the first 45 d Secondary endpoints: the rate of further bleeding and the rate of in-hospital complications

PPL: Plasma protein solution; PRC: Packed red cells; RCT: Randomized controlled trial; UGIB: Upper gastrointestinal bleeding.