Written by: Mediware Consulting and Analytics on Tuesday, April 23, 2013 Posted in: Blood Management


Hats off and ring the bell for Dr. Alam et al. for their upcoming article “The prevention of transfusion-associated circulatory overload” in Transfusion Medicine Reviews, anticipated in print April, 2013!  This review is outstanding as it guides us through the literature, both past and present, surrounding TACO, its definition, estimated incidence, identifiable risks factors, diagnosis, treatment options, and most importantly preventive strategies.

The article highlights data from several hemovigilance networks, the FDA, and additional U.S. cohort studies, along with a robust reference list.  The Quebec Hemovigilance System has reported a TACO rate of 1 in approximately 5500 RBC transfusions with a death rate of 1-3% .¹  Similiarly, the mortality rate due to TACO is reported as 3.6% by the French Hemovigilance System.²  Alam et al. cite a 2011 cohort study of ICU patients where the incidence of TACO was 6%.³  Our colleagues from Ontario are at the forefront of driving home the critical message that TACO is both under-recognized, under-reported and can be life-threatening.  Interestingly, Mediware Consulting & Analytics’ internal database (›8500 transfusion episodes in 60 centers) has revealed that 20% of TACO episodes, if recognized,  go unreported to the Transfusion Service.⁴

Alam and team provide an excellent table and discussion of the clinical factors that are strongly and consistently associated with TACO.  Clinical signs and testing that might aid in diagnosis are also listed.  There is a pre-transfusion assessment/ordering tool as well.  Pursuant to this useful prevention tool, two strong (and welcome) statements are made:  “As a first step, we recommend that all practitioners transfusing blood on a nonemergent basis perform mandatory pretransfusion risk assessment.”  This is followed by “Verbal orders for nonemergent blood products should be eliminated…[to prevent] potential harm arising from miscommunication and misunderstanding…”.   Now there’s a novel idea – pre-transfusion assessment?  Minimization of miscommunication and misunderstanding?  Bring it on!

Avoidance of unnecessary transfusion is highlighted as the key preventive measure.  If transfusion must occur, slowing the rate, decreasing total volume with single unit transfusion, use of infusion pumps and even pre-emptive diuretic use in high-risk patients should be considered.  Another nice table is provided as an aid for determining the need for diuretics.

Perhaps one of the most critical subsections in this article, from my view, is the content directed toward nursing supervision of transfusion.  We must all be aware and remember that transfusion is the #1 inpatient procedure performed and nurses represent the primary transfusionists in clinical situations outside of the operating suites or trauma massive transfusion protocols.  The authors speak very clearly that nurses can be the “definitive gatekeepers of unnecessary and improper transfusions…” and “should have the confidence and authority to question overzealous staff physicians and residents, who may not be aware of …guidelines and refuse verbal orders for nonemergent blood transfusions.”  Talk about empowerment!  I could not concur more.  Nursing leadership, supervision and collaboration are essential elements of effective, safe transfusion practices.

One last interesting finding noted by the authors is the incidence of TACO cases (11.3%) identified in the SHOT 2011 database which occurred between 6-24 hours after transfusion.⁵  This not only further emphasizes the need for continued patient monitoring long after the transfusion event, but could these represent late-onset TACO?  Will these cases, if studied, help us in our definition of the newly-described entity of transfusion-associated dyspnea (TAD)?

Of course the review concludes with the persistent call for awareness, more research, and guidance surrounding the entity of TACO.  No doubt about it, this article provides not only an excellent review of TACO as we know it (or don’t) today, but ends emphatically with the statement: “If a concerted effort is made worldwide to change our approach to the infusion of blood, a significant improvement in transfusion safety is within our reach.”

One word will suffice:  TOUCHE!


  1. Alam A et al.  The prevention of transfusion-associated circulatory overload,  Transfus Med Rev, 2013; epub, ahead of print;  http://dx.doi.org/10.1016/j.tmrv.2013.02.001
  2. Robillard P. et al. Transfusion, 2007; Suppl 47(35):47;5A
  3. David B. 27th Congress of the International society of blood Transfusion; 2002
  4. Li G et al. Transfusion, 2011;51:338
  5. Thomas J. et al. oral presentation, SABM, 2012
  6. Annual SHOT Report, 2011.Available from:  http://www.shotuk.org/shot-reports/shot-annual-report-summary-2011/.