Study supports only transfusing hip fracture patients who have signs of anemia

SAN DIEGO — The results of a large, randomized controlled trial showed no significant differences regarding the mortality and morbidity between patients undergoing hip fracture surgery who received transfusions when their hemoglobin level dropped below 10 g/dl and those who were only transfused when exhibiting anemia symptoms.

David W. Sanders, MD, MSc, FRCSC, presented the results of the functional outcomes in cardiovascular patients undergoing surgical hip fracture repair study, known as the FOCUS study, at the 2011 Annual Meeting of the American Academy of Orthopaedic Surgeons.

The study conducted at 47 U.S. and Canadian centers showed minimal differences between the liberal and restricted transfusion approaches.

David W. Sanders

“In total, if you look at the transfused units, this is the most glaring difference between the arms of the trial: 1,866 units transfused in the liberal group compared to just 652 [units] in the restrictive group,” Sanders said. “This did achieve a substantial hemoglobin difference post-randomization, averaging about 1.5 g/dl.”

Cardiac patients

More than 14,000 patients, most of whom had anemia with hemoglobin <10 g/dl, were screened for the study. Ultimately, 2,016 patients were randomized into two groups. Those in the restricted transfusion group were transfused only when they showed increased signs of anemia or when hemoglobin values reached 8 g/dl in an effort to maintain hemoglobin at 10 g/dl. Those in the liberally transfused group received blood whenever hemoglobin dropped below 10 g/dl.

Patients in both group had an average age of 82 years. Overall, 63% had cardiovascular disease and 37% had cardiovascular risk factors. Both groups had similar numbers of patients with either cardiovascular disease or cardiovascular risk factors.

More MIs in restrictive group

Investigators used an inability to walk without assistance or 60-day mortality following study enrollment as their primary endpoint. They found no significant differences between the groups based on these criteria. They also saw no differences based on 30-day and 60-day mortality alone.

The researchers also followed up with the patients by telephone to investigate whether patients developed complications. They also determined whether any cardiac events had occurred using a database that contained the results of serial electrocardiographs and troponin collections completed preoperatively, at randomization, and at day 1, day 4 or upon discharge. Nearly the same number of cardiac events was reported for both groups.

“One slight difference was 23 myocardial infarctions in the liberal group compared to 38 in the restrictive group,” which was not statistically significant, Sanders said.

A possible study limitation was the relatively low difference in hemoglobin levels separating the groups, he noted. – by Susan M. Rapp

Reference:

• Sanders D, Carson JL, Terrin ML, et al. Functional outcomes in cardiovascular patients undergoing surgical hip fracture repair (FOCUS). Paper #303. Presented at the 2011 Annual Meeting of the American Academy of Orthopaedic Surgeons. Feb. 15-19. San Diego.

• David W. Sanders, MD, MSc, FRCSC, can be reached at London Health Sciences Centre-Victoria Hospital, E4-123, 800 Commissioners Rd. East, London, Ontario N6A 5W9; 519-685-8086; email: ingrid.chivers@lhsc.on.ca.
• Disclosure: The study was funded by the National Institutes of Health-National Heart, Lung and Blood Institute. Sanders has no relevant financial disclosures.

Blood transfusions are counterintuitive in this high-risk population. Transfusing blood in cardiac patients with hematocrits in the mid-20 range may cause acute coronary syndrome, not prevent it. Transfusions also carry the risk of allergic reactions and disease transmission and are associated with wound infections and deep vein thrombosis, although the latter could be partially mitigated with regional anesthesia.

Blood transfusion did not affect the mortality-morbidity in this report, although the mortality-morbidity rate of 35% remains disturbing and has not changed in 50 years. Data seem to be consistently showing that lowering the transfusion trigger to 25 hematocrit is safe and may prevent most cardiac events. Perhaps the transfusion trigger could be set in the low 20 hematocrit range for some hemodynamically stable patients.

— Douglas E. Garland, MD
Orthopedics Today Editorial Board member
Long Beach, Calif.
Disclosure: He has no relevant financial disclosures.