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Emergency department staff knowledge of massive transfusion for trauma: the need for an evidence based protocol
  1. C Milligan1,
  2. I Higginson1,
  3. J E Smith1,2
  1. 1Emergency Department, Derriford Hospital, Plymouth, UK
  2. 2Academic Department of Military Emergency Medicine, Royal Centre for Defence Medicine, Birmingham, UK
  1. Correspondence to Claire Milligan, Emergency Department, Derriford Hospital, Plymouth PL68DH, UK; milli{at}doctors.org.uk

Abstract

Introduction Uncontrolled haemorrhage is the leading cause of potentially reversible early in-hospital death following trauma. Approximately 25% of trauma patients arriving in the emergency department have evidence of early coagulopathy. It is vital that staff within the emergency department understand the basic pathophysiological consequences of massive blood loss in trauma and are familiar with when and how to administer blood and specific blood components in trauma resuscitation.

Methods A structured questionnaire designed to test knowledge of the use of blood and blood components in trauma resuscitation was distributed to the emergency physicians attending a regional conference in the South West of England. The questionnaire consisted of 16 questions, both multiple choice and short answer format, referenced via Medline.

Results 32/32 questionnaires distributed were completed and returned. Massive transfusion protocols existed in 4/11 hospitals surveyed. 5/32 doctors were able to define the term ‘massive transfusion’ while 9/32, 6/32 and 3/32 were consistent with current guidelines in their prescription of platelets, fresh frozen plasma, and cryoprecipitate. 20/32 were consistent with current guidelines in identifying optimal haemoglobin levels. When asked more specifically about blood component therapy, 18/32 correctly identified target fibrinogen levels, 27/32 knew that fibrinogen is a component of fresh frozen plasma or cryoprecipitate and 1/32 correctly identified that fibrinogen is a component of both. 10/32 identified indications for beriplex and 5/32 doctors correctly identified indications for the use of recombinant factor VIIa. 20/32 doctors guessed >50% of the answers and the remaining 12/32 guessed 50%.

Conclusions The survey found that emergency physicians lacked core knowledge about the use of blood and blood component therapy in the context of massive haemorrhage following trauma. Doctors were unaware of how to prevent and treat early coagulopathy. Educational resources specifically for use by emergency physicians are limited on this topic. The use of massive transfusion protocols—that standardised blood component therapy is automatically delivered at specific points within resuscitation—would not only guide doctors, but be a clear step towards minimising the complications associated with massive transfusion.

  • Massive transfusion
  • emergency care systems
  • emergency departments
  • haematology
  • paramedics
  • education
  • trauma

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Introduction

Massive haemorrhage is responsible for the majority of preventable early traumatic deaths in patients reaching hospital.1–4 Bleeding is often a result of both primary vascular injury and secondary coagulopathy. Management should be directed towards early control of haemorrhage, but also prevention of coagulopathy, which may be a result of both traumatic haemorrhage and iatrogenic dilution. There is increasing evidence that early administration of blood and blood products in an appropriate population of trauma patients is of benefit in terms of morbidity and mortality.5–8 However, blood products are costly and often prescribed by junior members of staff with variable knowledge of the constituents of, and indications for, different blood products.

A massive transfusion protocol may be of benefit in standardising use of blood and blood products,9 and indeed reducing their overall use in the severely injured.10 Derriford Hospital is in the process of implementing a massive transfusion protocol for the management of patients with severe trauma. The aim of this study was to define the knowledge of emergency physicians in the South West of England with regard to administration of blood and blood products, and massive transfusion.

Methods

A questionnaire study was performed using a convenience sample of emergency physicians attending the South West Emergency Medicine Clinical Conference in Exeter in June 2008. The questionnaire was developed by the authors and consisted of 16 questions, both multiple choice and short answer format referenced via Medline. Questionnaires were distributed and completed during the 1-day conference. Data were analysed using a Microsoft Excel spreadsheet.

Results

Thirty-two emergency doctors completed the questionnaire (five consultants, 23 registrars, two staff grades, two unknown). Doctors from seven hospitals answered that there was a massive transfusion protocol designed to guide trauma resuscitation in their emergency department (ED). However, other doctors from three of these same EDs also stated there was no massive transfusion protocol. We have subsequently checked and 4/11 hospitals (Bristol Royal Infirmary, Bristol Children's Hospital, Frenchay and Swindon) in our region have a massive transfusion protocol which can be activated by ED staff following the arrival of trauma to the ED. Cheltenham and Gloucester have previously issued a ‘trauma pack’ but these are no longer in use. The other hospitals surveyed relied on trust intranet guidelines designed primarily for the management of upper gastrointestinal haemorrhage and not the trauma setting.

The definition of massive transfusion varied as per table 1. The correct answer is a 10 unit transfusion, transfusion of an entire blood volume in 24 h or replacement of 50% blood volume over 3 h.11 12 Of the 32 respondents only five gave the correct answer. Of the 23 registrars only three were able to provide correct definitions. The most popular definition overall was transfusion of >6 units. A quarter of doctors admitted they didn't know. When asked about target levels of Hb, platelets and fibrinogen in the context of trauma, answers were as shown in table 2. The correct answers are Hb 8 g/dl, platelet 75×109 (this trigger is set to prevent the actual count falling below 50×109, and 100×109 may be more appropriate in high velocity trauma or central nervous system injury), fibrinogen >1.0 g/l.11 12

Table 1

Emergency department physician's definitions of ‘massive transfusion’

Table 2

Emergency department physician's definitions of ideal target levels of haemoglobin (Hb), fibrinogen and platelets in trauma

There was variable knowledge about the effects of massive blood transfusion and when to start using other blood products, as shown in table 3. Fresh frozen plasma (FFP) should definitely be given after 6 units but ideally before (optimal ratio 1:1.8 and there is now increasing evidence to suggest a ratio of 1:1 may be more appropriate); 6/32 answered correctly. Platelets should be given after 10 units (1 aphoresis is equal to 10–11 units) or sooner if smaller pools are used6 13; 9/32 gave correct answers. Low fibrinogen may prompt transfusion of either FFP or cryoprecipitate as both contain fibrinogen. In all, 27/32 identified that fibrinogen was a component of either FFP or cryoprecipitate; only 1/32 correctly identified both as a source. Replacing 50% of the total blood volume will reduce the platelet count by approximately 50%14 15; 7/32 doctors were correct in their answers, the remainder opting for a reduction of 25% (13/32), 33% (3/32) or 75% (9/32). Just 6/32 identified the risk of transfusion reaction following uncross matched blood as 0.1–0.5%,7 14/32 thought the risk was 5%, 4/32 10% and 7/32 >10%. One doctor failed to answer. Knowledge about the components of red blood cells, FFP and cryoprecipitate was variable in keeping with the other results of the questionnaire.

Table 3

Prescribing habits of emergency department physicians regarding platelets, fresh frozen plasma and cryoprecipitate

Only 10/32 respondents were able to give recognised indications for beriplex,11 and only 5/32 were able to identify indications for the use of recombinant factor VIIa12 13 16 (table 3). In addition, 56% of the respondents did not know if recombinant activated factor VIIa was available in their hospital.

Finally, 12 respondents admitted to guessing at least 50% of the answers and the remaining 20 to guessing >50%. This in itself is perhaps the most telling result.

Discussion

Historically the administration of blood and blood products such as platelets, plasma and cryoprecipitate has been dependent on abnormal laboratory measures of coagulation (prothrombin time or activated partial thromboplastin time >1.5 control) and platelet count. However, clinicians are aware that by the time laboratory values have become abnormal, it is often too late to correct exsanguination in patients with severe haemorrhage. The coagulopathy of trauma is multi-factorial, but one of the most important factors is depletion of coagulation factors, from dilution during resuscitation with crystalloid and packed red blood cells.17 18 The establishment of a massive transfusion protocol aims to anticipate and pre-empt worsening coagulopathy in trauma by early administration of platelets and coagulation factors in addition to red blood cells.19 The knowledge of the use of blood components among those doctors completing this survey would support the notion that standardising blood transfusion in major trauma to include automatic delivery of appropriate blood products at particular points in resuscitation maybe of benefit.

Key facts regarding blood transfusion in trauma

  • Massive transfusion is defined as 10 unit transfusion, transfusion of 50% of patients blood volume within 3 h or transfusion of a patients total blood volume within 24 h

  • A unit of packed red blood cells also contains lactate, potassium and citrate

  • Target Hb >8 g/dl

  • Target platelets >75×109 (unless multi-trauma/central nervous system injury or platelet abnormality when levels of 100×109 are beneficial)

  • Target fibrinogen >1.0 g/l

  • Platelet counts fall by 50% if blood volume is replaced

  • Risk of a transfusion reaction following un-crossmatched blood is 0.1–0.5%

  • Indications for recombinant factor VIIa include uncontrolled haemorrhage failing to respond to surgical and non-surgical methods including replacement and correction of blood components

  • Indications for Prothrombin Concentrate Complex (Beriplex) in trauma include haemophilia or a life-threatening bleed in patients on warfarin

References

Footnotes

  • Competing interests None.

  • Provenance and peer review Not commissioned; externally peer reviewed.

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