title: Blood transfusion after cardiac surgery: is it the patient or the transfusion that carries the risk?
abstract: BACKGROUND
  The transfusion of red blood cells (RBCs) after cardiac surgery has been associated with increased long-term mortality. This study reexamines this hypothesis by including pre-operative hemoglobin (Hb) levels and renal function in the analysis.
  
  
  METHODS
  A retrospective single-center study was performed including 5261 coronary artery bypass grafting (CABG) patients in a Cox proportional hazard survival analysis. Patients with more than eight RBC transfusions, early death (7 days), and emergent cases were excluded. Patients were followed for 7.5 years. Previously known risk factors were entered into the analysis together with pre-operative Hb and estimated glomerular filtration rate (eGFR). In addition, subgroups were formed based on the patients' pre-operative renal function and Hb levels.
  
  
  RESULTS
  When classical risk factors were entered into the analysis, transfusion of RBCs was associated with reduced long-term survival. When pre-operative eGFR and Hb was entered into the analysis, however, transfusion of RBCs did not affect survival significantly. In the subgroups, transfusion of RBCs did not have any effect on long-term survival.
  
  
  CONCLUSIONS
  When pre-operative Hb levels and renal function are taken into account, moderate transfusions of RBC after CABG surgery do not seem to be associated with reduced long-term survival.
authors.affiliation: Department of Anesthesia and Intensive Care, Lund University Hospital, Lund University, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Dardashti
authors.forename: P
authors.initials: P
authors.lastname: Ederoth
authors.forename: L
authors.initials: L
authors.lastname: Algotsson
authors.forename: B
authors.initials: B
authors.lastname: Brondén
authors.forename: C
authors.initials: C
authors.lastname: Lührs
authors.forename: H
authors.initials: H
authors.lastname: Bjursten
mesh_terms: D000368:Aged; D015992:Body Mass Index; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D015331:Cohort Studies; D001026:Coronary Artery Bypass; D016208:Databases, Factual; D017707:Erythrocyte Transfusion / Q000009:adverse effects; D005260:Female; D005919:Glomerular Filtration Rate; D006454:Hemoglobins / Q000032:analysis / Q000378:metabolism; D006801:Humans; D053208:Kaplan-Meier Estimate; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000009:adverse effects*; D011183:Postoperative Complications / Q000401:mortality; D011184:Postoperative Period; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012306:Risk; D016019:Survival Analysis; D065227:Transfusion Reaction; D016896:Treatment Outcome
chemical_list: D006454:Hemoglobins