News and Articles
Increased Mortality, Postoperative Morbidity, and Cost After Red Blood Cell Transfusion in Patients Having Cardiac Surgery
Type: Reference library
Date Posted: Wednesday, November 28th, 2007
based on 4 readers · Rate this article| Murphy GJ, Reeves BC, Rogers CA, Rizvi SI, Culliford L, Angelini GD. Circulation. 2007 Nov 12; [Epub ahead of print] Bristol Heart Institute, University of Bristol, Bristol, United Kingdom |
| Abstract Here |
| Summary |
| The authors of this UK study conclude that red blood cell transfusion appears to be harmful for almost all heart surgery patients and wastes scarce health resources. This single-center retrospective cohort study of over 5,800 patients employing multivariable logistic regression and propensity score analysis contains new finds that challenge current beliefs about transfusion indications, particularly those based on hematocrit value, age, comorbidities and assumptions about improving tissue oxygenation. The investigators collected predetermined data from 3 databases (clinical, hematology and transfusion), intensive care unit (ICU) charts and a population register of all adult patients undergoing cardiac surgery over an 8-year period comparing transfused versus non-transfused patients. Primary outcomes were composite infection (respiratory or wound infections or septicemia) and composite ischemic events (myocardial infarction, stroke or renal complications). Secondary outcomes included hospital costs, length of stay and survival. The investigators found that transfusion was strongly associated with increased infection – over 3-fold higher in transfused patients compared with non-transfused. One new finding was that transfusion was associated with a greater than 3-fold adjusted increased risk of ischemic events. The authors state that this finding was unexpected as they included the ischemic events outcome measure in the study with the belief that it would identify compromised tissue oxygenation in patients not transfused when their nadir hematocrit was very low. The authors also identified a dose-dependent relationship between transfusion and the two primary outcome measures. The risks increased with the number of units transfused. An additional new finding was that these outcomes did not differ when analyzed by nadir hematocrit and patient risk factors. The authors state that this finding does not support current recommendations for more liberal transfusion thresholds for elderly and high-risk patients. In the current study there was no noticeable benefit derived from RBC transfusion at hematocrits as low as 21%. Of further interest, universal leukodepletion was introduced in the UK three and one half years into the study period. The study did not find any evidence that leukodepletion reduced infection. Other findings of the study were that transfusion was associated with increased ICU, high-dependency unit and hospital length of stay and a 40% increase in overall hospital costs. The 30-day mortality rate was over 6-times higher in the transfused patients and increased mortality was observed up to 7 years after surgery. The authors conclude that this study argues against the proposition that the adverse outcomes associated with transfusion are a result of sicker patients receiving transfusions rather than the transfusion per se. The authors state that they believe the harmful effect of transfusion is real. They hope that these finds will serve as an impetus for governments to invest in research to address issues raised by this study. |