Identifying patients at risk of intraoperative and postoperative transfusion in isolated CABG: toward selective conservation strategies.
BACKGROUND
Allogeneic blood product use during cardiac operation is often reported to exceed 40% despite published guidelines and costly blood conservation strategies. We developed a predictive model, based on eight preoperative risk factors, of allogeneic blood product transfusion rates in patients undergoing a cardiac procedure.


METHODS
All 3,046 consecutive, isolated coronary artery bypass graft (CABG) procedures at a university hospital from 1995 to 1998 were included. A logistic regression model was created to identify independent predictors of allogeneic blood product transfusion. This model was validated using a prospective patient sample.


RESULTS
Overall use of allogeneic blood products was 23% with a crude operative mortality of 2.1%. In isolated, elective, first-time CABG cases, 16.9% received allogeneic blood products. Independent predictors of blood product usage in CABG patients were preoperative hemoglobin 12.0 or less, emergent operation, renal failure, female sex, age 70 years or older, left ventricular ejection fraction 0.40 or less, redo procedure, and low body surface area. Prospective validation of this model on 2,117 consecutive isolated CABG patients demonstrated an observed-to-expected allogeneic blood product transfusion rate ratio of 1.06.


CONCLUSIONS
This internally validated logistic regression risk model is a sensitive and specific predictor of allogeneic blood product use in patients undergoing isolated CABG. Utilization of this model allows for preoperative risk stratification and may allow for more rational resource allocation of costly blood conservation strategies and blood bank resources.
Arora
Rakesh C
RC
Division of Cardiac Surgery, Dalhousie University, Halifax, Nova Scotia, Canada.
Légaré
Jean-Francois
JF
Buth
Karen J
KJ
Sullivan
John A
JA
Hirsch
Gregory M
GM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015119:Aminocaproic Acid / Q000627:therapeutic use; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use; D016913:Blood Component Transfusion / Q000706:statistics & numerical data; D016063:Blood Loss, Surgical / Q000706:statistics & numerical data; D001803:Blood Transfusion / Q000706:statistics & numerical data*; D015897:Comorbidity; D047549:Coronary Artery Bypass, Off-Pump / Q000706:statistics & numerical data*; D016208:Databases, Factual; D004630:Emergencies; D005260:Female; D006493:Heparin / Q000009:adverse effects / Q000627:therapeutic use; D006785:Hospitals, University / Q000706:statistics & numerical data; D006801:Humans; D007423:Intra-Aortic Balloon Pumping / Q000706:statistics & numerical data; D007430:Intraoperative Care; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D009674:Nova Scotia; D010952:Plasma Substitutes / Q000627:therapeutic use; D011182:Postoperative Care; D019106:Postoperative Hemorrhage / Q000453:epidemiology / Q000628:therapy; D011446:Prospective Studies; D012189:Retrospective Studies; D018570:Risk Assessment; D014148:Tranexamic Acid / Q000627:therapeutic use
D000925:Anticoagulants; D010952:Plasma Substitutes; D014148:Tranexamic Acid; D006493:Heparin; D015119:Aminocaproic Acid