Clinical Abstracts
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June 2012 Editors:
Thresholds for postoperative transfusion for patients with known risk factors for cardiovascular disease are often set at lower hemoglobin concentrations. However, this practice is controversial, and because transfusion is not without risk, restricting transfusions may result in better outcomes. The authors conducted a study to determine if patients older than 50 years of age who had a history of cardiovascular disease or risk factors for the disease would benefit from a more liberal or restrictive transfusion strategy. Patients undergoing hip fracture surgery were randomly assigned to receive transfusions at a liberal threshold of 10 g/dL or a restrictive threshold of less than 8 g/dL. The primary outcome was death or inability to walk across the room without human assistance at 60-day followup. The study enrolled 2,016 patients and analyzed data from 1,999 of those patients. The average number of transfused units in the liberal group was two and in the restrictive group was zero. Outcomes showed that the rates of death and inability to walk without assistance at 60 days were similar in the restrictive and liberal strategy groups. Furthermore, the authors found no significant differences in rates of death on 30-day followup between the two groups. And the rates of in-hospital acute myocardial infarction, unstable angina, and death were not significant between the two cohorts. Despite no differences in measured outcomes, the study did show a clinical difference in the utilization of packed red blood cells—patients in the restrictive group received 65 percent fewer units compared to those in the liberal group. In addition, a higher odds ratio for males compared to females was noted in the liberal strategy group when comparing outcomes of death or inability to walk without assistance at 60 days. The authors noted that, although unanticipated, they do not believe these findings are due to chance. They concluded that neither a liberal nor restrictive transfusion strategy appears to be associated with increased morbidity and mortality. This suggests that patients without signs or symptoms of anemia may tolerate a higher threshold for transfusion in the postoperative period, even if they have cardiovascular risk factors. Carson JL, Terrin ML, Noveck H, et al. Liberal or restrictive transfusion in high-risk patients after hip surgery. N Engl J Med. 2011; 365:2453–2462. Correspondence: Dr. Jeffrey L. Carson at carson@umdnj.edu [ Top ]
The introduction of personalized medicine has challenged the health care community to provide greater amounts of information to patients in a safe and reliable manner. On Sept. 14, 2011, the Department of Health and Human Services, Centers for Medicare & Medicaid Services, Centers for Disease Control and Prevention, and Office for Civil Rights proposed a rule to allow patients to access test results directly from the laboratory in a paper or electronic format by request. Giardina and Singh addressed the pros and cons of such reform in a commentary summarized here. Although intended as a benefit to the patient, the authors expressed concerns with the proposed rule with respect to the patient. The proposed law would require all CLIA and CLIA-exempt clinical laboratories to comply with HIPAA regulations, thereby standardizing patients’ rights to access their laboratory test results. The rule would have the most effect in the 39 states and territories in which there is either no rule or law governing direct test result delivery to patients or the practice is prohibited by state law. However, the proposed rule does not specify which types of tests require physician review first or if there is a waiting period before sending out results. Giardina and Singh noted that patients may view direct access to test results as a benefit that may help them become more involved in their own medical decisionmaking. Yet the authors stated that there is limited data to support this viewpoint. How patients may receive their abnormal test results is not addressed in the proposed rule and has the potential to lead to more unanswered questions for the patient. The authors also suggested that providing patients access to their lab test results could negatively affect followup care as both the physician and patient may assume that the other party has the obligation to followup. However, the proposal suggests that direct patient access to lab test results would decrease physician workload, reduce the number of patients not receiving notification of test results, and reduce the risk of loss of followup. Yet clear evidence to support these claims is lacking. In addition, the proposal does not offer clear guidance on releasing highly sensitive test results, such as those for HIV, abnormal pathology, and genetic testing, leaving physicians to struggle with the best method for communicating with patients. In these scenarios, face-to-face communication may reduce patient anxiety and confusion, but direct access to results may hinder this mode of communication. The authors also suggested that patients responding to results that are abnormal but not clinically significant may increase physician workload and efficiency. Giardina and Singh concluded that the roles of physicians and patients would need to change under this proposed rule and suggested rigorous evaluation of best practices to avoid unintended consequences. Giardina TD, Singh H. Should patients get direct access to their laboratory test results? An answer with many questions. JAMA. 2011;306:2502–2503. Correspondence: Dr. Hardeep Singh at hardeeps@bcm.edu [ Top ]
The current practice in hospital blood banks is to issue ABO-identical or ABO-compatible red blood cells and fresh frozen plasma. However, platelets and cryoprecipitate are not routinely ABO matched due to minimal concerns with contaminating red blood cells and hemolysis due to anti-A, anti-B, and soluble ABH antibodies in plasma. Yet transfusing ABO-nonidentical platelets carries a real, albeit small, risk for a hemolytic reaction. Older studies demonstrated that ABO-nonidentical platelets may increase rates of alloimmunization and decrease post-transfusion count increments. Other studies have demonstrated an association between forming immune complexes and an increase in mortality with the use of ABO-nonidentical platelets. In this study, Henrichs and colleagues implemented a policy to transfuse only ABO-identical components when possible and studied the impact of this approach on transfusion reactions and alloimmunization. The primary outcome measures were product wastage, transfusion reactions, and red blood cell alloimmunization rates for four years before and after implementing the policy. When no ABO-identical platelets were available, platelets were washed to remove incompatible plasma. The results showed a statistically significant increase in whole blood platelet wastage and a decrease in febrile transfusion reactions. In regard to alloimmunization, the study showed a 50 percent decrease in the incidence of new red blood cell alloantibodies. However, the authors noted study limitations, including lack of randomization and the use of event-level data. Therefore, the outcome data may be an overestimation of variations from the true incidence. The authors concluded that they showed the feasibility of providing ABO-identical components to almost all patients at their institution and the benefits with regard to transfusion reactions and alloimmunization rates. Additional clinical studies—possibly randomized controlled trials—are necessary to determine the overall effects and benefits of such an ABO policy. Henrichs KF, Howk N, Masel DS, et al. Providing ABO-identical platelets and cryoprecipitate to (almost) all patients: approach, logistics, and associated decreases in transfusion reaction and red cell alloimmunization incidence. Transfusion. 2012;52:635–640. Correspondence: Neil Blumberg at neil_blumberg@urmc.rochester.edu [ Top ]Clinical pathology abstracts editors: Deborah Sesok-Pizzini, MD, MBA, associate professor, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, and medical director, Blood Bank and Transfusion Medicine, Children’s Hospital of Philadelphia; Tina Ipe, MD, MPH, resident, Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania. |
