Free
Correspondence  |   March 2017
Liberal versus Restrictive Erythrocyte Transfusion Algorithms and Perioperative Outcomes: Statistical Significance and Pulmonary Complications
Author Notes
  • Mayo Clinic, Rochester, Minnesota. warner.matthew@mayo.edu
  • (Accepted for publication October 20, 2016.)
    (Accepted for publication October 20, 2016.)×
Article Information
Correspondence
Correspondence   |   March 2017
Liberal versus Restrictive Erythrocyte Transfusion Algorithms and Perioperative Outcomes: Statistical Significance and Pulmonary Complications
Anesthesiology 3 2017, Vol.126, 569. doi:10.1097/ALN.0000000000001450
Anesthesiology 3 2017, Vol.126, 569. doi:10.1097/ALN.0000000000001450
To the Editor:
It was with great interest that I read the recent meta-analysis by Hovaguimian and Myles1  and the accompanying editorial by Beattie and Wijeysundera2  regarding liberal versus restrictive erythrocyte transfusion triggers for surgical patients and those admitted to acute care environments. Their efforts in addressing the importance of clinical context (e.g., surgical type, comorbid disease) when evaluating transfusion algorithms should be congratulated. There are, however, several additional items deserving of mention.
First, Hovaguimian and Myles1  state that in those undergoing cardiovascular procedures, restrictive transfusion strategies increased the risk of mortality (risk ratio [RR], 1.39; 95% CI, 0.95 to 2.04) and events reflecting inadequate oxygen supply (RR, 1.09; 95% CI, 0.97 to 1.22). This statement is also highlighted in the section titled “What This Article Tells Us That Is New” and in the “Perioperative and Acute Care Transfusion Strategies” figure by Wanderer and Rathmell.3  However, an RR crossing a threshold of 1 does not imply statistical significance and should be labeled accordingly as a nonsignificant result.
A second thing to consider when interpreting the study results is that transfusion-related pulmonary complications, including transfusion-related acute lung injury and transfusion-related circulatory overload, were not included in the analysis. As these remain the leading causes of transfusion-related morbidity and mortality and are likely more prevalent than clinically diagnosed or reported,4,5  readers should be mindful of their exclusion and the potential implications with more liberal transfusion practices.
Again, I congratulate the authors on their tremendous contribution to this important perioperative topic. While there is much work to be done, this is a large step forward.
Research Support
Supported by the Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota.
Competing Interests
The author declares no competing interests.
Matthew A. Warner, M.D., Mayo Clinic, Rochester, Minnesota. warner.matthew@mayo.edu
References
Hovaguimian, F, Myles, PS . Restrictive versus liberal transfusion strategy in the perioperative and acute care settings: A context-specific systematic review and meta-analysis of randomized controlled trials. Anesthesiology. 2016;125:46–61. [Article] [PubMed]
Beattie, WS, Wijeysundera, DN . Approaching a safe last resort: Triggers for perioperative blood transfusion. Anesthesiology. 2016;125:11–3. [Article] [PubMed]
Wanderer, JP, Rathmell, JP . Perioperative and acute care transfusion strategies: One size may not fit all. Anesthesiology. 2016;125:A21
Clifford, L, Jia, Q, Subramanian, A, Yadav, H, Wilson, GA, Murphy, SP, Pathak, J, Schroeder, DR, Kor, DJ . Characterizing the epidemiology of postoperative transfusion-related acute lung injury. Anesthesiology. 2015;122:12–20. [Article] [PubMed]
Clifford, L, Jia, Q, Yadav, H, Subramanian, A, Wilson, GA, Murphy, SP, Pathak, J, Schroeder, DR, Ereth, MH, Kor, DJ . Characterizing the epidemiology of perioperative transfusion-associated circulatory overload. Anesthesiology. 2015;122:21–8. [Article] [PubMed]