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.

Supported by the Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota.

The author declares no competing interests.

1.
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
.
2.
Beattie
WS
,
Wijeysundera
DN
:
Approaching a safe last resort: Triggers for perioperative blood transfusion.
Anesthesiology
2016
;
125
:
11
3
.
3.
Wanderer
JP
,
Rathmell
JP
:
Perioperative and acute care transfusion strategies: One size may not fit all.
Anesthesiology
2016
;
125
:
A21
4.
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
.
5.
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
.