NEW YORK (Reuters Health) – The percentage of cardiac surgery patients given blood transfusions varies widely from center to center, but a conservative use of transfusions is not detrimental to outcomes. Those conclusions come from two papers in the Journal of the American Medical Association for October 13.
In the first study, Dr. Elliott Bennett-Guerrero with Duke University Medical Center, in Durham, North Carolina, and colleagues note that there have been many initiatives to reduce perioperative blood transfusions. To see how rates vary, the team examined data in the Society of Thoracic Surgeons Adult Cardiac Surgery database.
“At hospitals performing at least 100 on-pump CABG operations (82,446 cases at 408 sites), the rates of blood transfusion ranged from 7.8% to 92.8% for RBCs, 0% to 97.5% for fresh-frozen plasma, and 0.4% to 90.4% for platelets,” the researchers report.
Case mix, hospital location, academic status and volume explained no more than a third of the variation between hospitals.
Meanwhile, an international group has investigated the safety a restrictive perioperative red blood cell transfusion strategy versus a liberal strategy in patients undergoing elective cardiac surgery.
In a randomized controlled trial conducted at a university hospital referral center in Brazil, 502 consecutive patients undergoing cardiac surgery with cardiopulmonary bypass were assigned to receive transfusions aimed at maintaining a hematocrit of at least 30% (liberal strategy) or 24% (restrictive strategy). The main outcome measure was a composite of in-hospital mortality or severe morbidity, i.e., cardiogenic shock, ARDS, or acute renal Injury.
Dr. Jean-Louis Vincent of Erasme University Hospital in Brussels, Belgium, and colleagues found the composite endpoint occurred in 10% of the liberal strategy group and 11% of the restrictive strategy group, a nonsignificant difference at a p value of 0.85.
On the hand, 30-day mortality and complications increased with the number of RBC units transfused, regardless of transfusion strategy, with a hazard ratio of 1.25 per additional unit (p=0.002).
The authors conclude, “Using a noninferiority margin of -8% among patients undergoing elective cardiac surgery, the use of a restrictive perioperative transfusion strategy compared with a more liberal strategy resulted in noninferior rates of the combined outcome of 30-day all-cause mortality and severe morbidity.”
In an editorial, Dr. Lawrence Tim Goodnough of Stanford University School of Medicine, California, and Dr. Aryeh S. Shander at Englewood Hospital and Medical Center, New Jersey say that “continued inappropriate transfusions among hospitals is a major concern.”
They note that the Society of Thoracic Surgeons’ rating measures for cardiac surgery programs do not include RBC transfusions as a quality indicator. They suggest, “It may be time for patient blood management to gain status as a performance indicator by accreditation agencies such as the Joint Commission or as a quality indicator by professional organizations such as the Society of Thoracic Surgeons as part of transparency and public rankings for consumers.”
JAMA 2010;304:1559-1575,1610-1611.
