15th May 2014 Lab vs ratio transfusion strategies

Presented by Dr Chiara Robba

This paper is a significant contribution to one of the most active areas of research in trauma critical care, the titration of blood products during and following massive haemorrhage.

The concept of a 1:1:1 transfusion ratio developed from the experience of the military in Iraq and Afghanistan, this blog article has a good selection of key references (by an Italian from Brescia!). However the efficacy of this strategy in military patients has not been reliably replicated in civilian patients and trials are underway to attempt to identify the optimum ratio, for example PROPPR.

A 1:1:1 strategy is, however, potentially unsafe, expensive and perhaps consumes valuable resources unnecessarily. Rather than wait for trials to establish the correct transfusion ratio considerable efforts are being expended to identify laboratory or POCT systems to guide resuscitation during massive haemorrhage.

Progress is patchy, however, possibly because the field is complicated with an overlapping set of questions; firstly what should we transfuse patients with during empirical treatment, secondly how should we define and measure acute coagulopathy of trauma, and thirdly how should we reverse coagulopathy once we have diagnosed it.

This paper is an important contribution to teasing out all three questions and starts to provide some answers. Essentially they have asked whether a ratio based transfusion strategy is better than a lab based strategy using a range of clinical, safety and economic outcomes. It is a small study but the really interesting part of this paper is that they have used INR, APTT and fibrinogen rather than TEG or RoTEM which, perhaps, would have been the intuitive choice.

This paper begs the question: should we wait for the ratio trials or develop a lab/POCT based transfusion strategy?

Unsurprisingly the range of resources and opinions on this topic is extensive:

letter from Manchester in response to the paper which summarises the debate well.

Military meta-analysis.

BJA review

EMCrit podcast

Some useful sources on LITFL

Karim Brohi talks well on this topic and there are some interestinglectures on the ESICM site.

Next week we will discuss blood pressure control in intracerebral haemorrhage.