Blood Transfusions Are Often Overdone in Cardiac Surgery

The use of blood transfusions during and after cardiac surgery is common. However, possible problems with patients receiving blood led researchers at Ann Arbor, Michigan, to study outcomes following coronary artery bypass surgery in relation to the use of blood transfusion. Their report appears in BMC Medicine.

Bypass Medicare patient records from 40 hospitals in the state of Michigan were analyzed from 2003 to 2006. Data obtained from almost 25,000 such patients included transfusions, in-hospital infection and mortality, and readmission and mortality 30 days after discharge.

Blood use among women patients ranged from 73% to 100%, and among men from 50% to 100%, depending largely on the particular hospital. The follow-up data showed that blood transfusion doubled the odds of in-hospital infection, increased in-hospital mortality 4.7-fold, 30-day readmission 1.4-fold, and 30-day mortality 2.9-fold. Infections of the urinary tract, respiratory tract, bloodstream, digestive tract, and skin were increased 0.13% for every 1% increase in hospital transfusion rates.

The fact that there was considerable variation in transfusion practices between hospitals, and that there were clear associations between blood use, infection, and mortality, suggests that there must be room for guidelines discouraging blood transfusion, as far as possible, for this procedure. This may be an example of the opportunity for a significant healthcare economy through evidence-based guidelines.