Reply
We thank the readers for their letter to the editor, and for interest in our manuscript published in 2014. Issues surrounding blood management continue to be an important part of the global care of total joint arthroplasty patients as we move into 2017. In addition to our group's multiple studies on the use of bipolar sealing devices in joint arthroplasty,12) we continue to examine our blood management and transfusion practices. We now routinely employ the use of tranexamic acid, which has further allowed a reduction in transfusion requirements. This may account for some of the differences between contemporary rates of transfusion, and historical rates presented before the routine use of tranexamic acid.
We thank the readers for inquiring about the transfusion reduction rates as presented in our manuscript. The absolute reduction in transfusion rate was 83% to 55%, a difference of 28% points. The relative reduction as a percentage of the original transfusion rate of 83% would be approximately 35%. In a simpler comparison, for example, if the transfusion rate was reduced from 10% to 5%, we would have stated that there was an absolute reduction of 5% but a 50% reduction from the baseline rate (5%/10% = 0.5). In our manuscript, we acknowledge some of the limitations discussed by the readers' letter to the editor. This study was not a prospective randomized controlled trial, and therefore issues of blinding and randomization do not apply. Rather, our study has important applications for real-world transfusion scenarios based on clinical scenario and patient comorbid conditions. We thank the readers for sharing their own data and algorithm for management, which, like our practice, involves careful evaluation of “comorbidity and cardiorespiratory risk, ongoing blood loss, and symptoms related to anaemia.” Likewise, confounders of age and dilutional anaemia are important considerations in any study of blood management, but are not controlled for in our clinical practice review.
Again, we thank the readers for their letter to the editor, as well as their own institutional efforts to examine transfusion thresholds, understand adjunctive tools in blood management, and further the perioperative care of total joint patients.