Lack of evidence, not knowledge, contributes to variability in massive transfusion practice
Milligan, et al. (1) provides valuable insight into the varied management of massive haemorrhage post trauma. However, the conclusions that emergency physicians lacked core knowledge and were unaware of how to prevent and treat early coagulopathy appear unfounded. It would be more prudent to conclude that a paucity of high level of evidence guiding trauma resuscitation was responsible for this varied practice.
The definition of massive transfusion has little clinical significance during trauma resuscitation and even so, remains debated with an acute definition likely to be more effective than the traditional definition. (2) Massive blood transfusion during trauma resuscitation is rarely based on a target haemoglobin and current experience with thromboelastography suggests that platelet function rather than absolute platelet counts should direct platelet transfusion. The ideal ratio of packed red blood cells to fresh frozen plasma similarly has been gleaned from retrospective associations only, confounded by multiple biases. Recent randomised controlled trials have failed to show any outcome benefit from the stated indication for recombinant factor VIIa.
Attempts to develop massive transfusion protocols supported by inadequate evidence have previously resulted in marked variability in practice.(3) A massively haemorrhaging trauma patient presents a challenging scenario to most emergency physicians and in the face of poor level of evidence to guide practice, it is not surprising that most use clinical gestalt (referred by the authors as "guess"). Rather than criticising the knowledge of emergency physicians or imposing non-evidence based "protocols", research efforts should be directed at multicentre, outcome focused randomised controlled trials comparing different but valid strategies in managing massive haemorrhage. Only then can we embark on developing effective massive transfusion guidelines.
1. Milligan C, Higginson I, Smith JE. Emergency department staff knowledge of massive transfusion for trauma: the need for an evidence based protocol. Emerg Med J. 2010 (In Press). doi:10.1136/emj.2009.088138.
2. Mitra B, Cameron PA, Gruen R, et al. The definition of massive transfusion in trauma: a critical variable in examining evidence for resuscitation. Eur J Emerg Med. 2010 (In Press). doi: 10.1097/MEJ.0b013e328342310e
3. Schuster KM, Davis KA, Lui FY, et al. The status of massive transfusion protocols in United States trauma centers: massive transfusion or massive confusion? Transfusion 2010; 50(7): 1545-1551.
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