Article Text

Identification of major hemorrhage in trauma patients in the prehospital setting: diagnostic accuracy and impact on outcome
  1. Jared M Wohlgemut1,2,
  2. Erhan Pisirir3,
  3. Rebecca S Stoner1,2,
  4. Evangelia Kyrimi3,
  5. Michael Christian4,
  6. Thomas Hurst4,
  7. William Marsh3,
  8. Zane B Perkins1,2,
  9. Nigel R M Tai1,2
  1. 1Centre for Trauma Sciences, Blizard Institute, Queen Mary University of London, London, UK
  2. 2Trauma Service, Royal London Hospital, Barts Health NHS Trust, London, UK
  3. 3School of Electronic Engineering and Computer Science, Queen Mary University of London, London, UK
  4. 4London’s Air Ambulance, London, UK
  1. Correspondence to Dr Jared M Wohlgemut; jwohlgemut{at}


Background Hemorrhage is the most common cause of potentially preventable death after injury. Early identification of patients with major hemorrhage (MH) is important as treatments are time-critical. However, diagnosis can be difficult, even for expert clinicians. This study aimed to determine how accurate clinicians are at identifying patients with MH in the prehospital setting. A second aim was to analyze factors associated with missed and overdiagnosis of MH, and the impact on mortality.

Methods Retrospective evaluation of consecutive adult (≥16 years) patients injured in 2019–2020, assessed by expert trauma clinicians in a mature prehospital trauma system, and admitted to a major trauma center (MTC). Clinicians decided to activate the major hemorrhage protocol (MHPA) or not. This decision was compared with whether patients had MH in hospital, defined as the critical admission threshold (CAT+): administration of ≥3 U of red blood cells during any 60-minute period within 24 hours of injury. Multivariate logistical regression analyses were used to analyze factors associated with diagnostic accuracy and mortality.

Results Of the 947 patients included in this study, 138 (14.6%) had MH. MH was correctly diagnosed in 97 of 138 patients (sensitivity 70%) and correctly excluded in 764 of 809 patients (specificity 94%). Factors associated with missed diagnosis were penetrating mechanism (OR 2.4, 95% CI 1.2 to 4.7) and major abdominal injury (OR 4.0; 95% CI 1.7 to 8.7). Factors associated with overdiagnosis were hypotension (OR 0.99; 95% CI 0.98 to 0.99), polytrauma (OR 1.3, 95% CI 1.1 to 1.6), and diagnostic uncertainty (OR 3.7, 95% CI 1.8 to 7.3). When MH was missed in the prehospital setting, the risk of mortality increased threefold, despite being admitted to an MTC.

Conclusion Clinical assessment has only a moderate ability to identify MH in the prehospital setting. A missed diagnosis of MH increased the odds of mortality threefold. Understanding the limitations of clinical assessment and developing solutions to aid identification of MH are warranted.

Level of evidence Level III—Retrospective study with up to two negative criteria.

Study type Original research; diagnostic accuracy study.

  • diagnostic accuracy
  • hemorrhage
  • multiple trauma
  • diagnosis

Data availability statement

Data may be obtained from a third party and are not publicly available. Data may be obtained from Barts Health NHS Trust and are not publicly available.

This is an open access article distributed in accordance with the Creative Commons Attribution 4.0 Unported (CC BY 4.0) license, which permits others to copy, redistribute, remix, transform and build upon this work for any purpose, provided the original work is properly cited, a link to the licence is given, and indication of whether changes were made. See:

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

Data availability statement

Data may be obtained from a third party and are not publicly available. Data may be obtained from Barts Health NHS Trust and are not publicly available.

View Full Text

Supplementary materials

  • Supplementary Data

    This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.


  • Presented at This work was presented as an Oral Presentation at the 22nd European Congress of Trauma and Emergency Surgery in Ljubljana, Slovenia, May 7-9, 2023, and was a recipient of the TSACO Resident Paper Competition.

  • Contributors All authors contributed to the study’s conception and design. Material preparation, data collection and analysis were performed by JMW. The first draft of the manuscript was written by JMW, and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. JMW was the guarantor of the study.

  • Funding JMW, EP, RSS, EK, WM, ZBP, and NRMT have received research funding from the US Department of Defense: a precision trauma care research award from the Combat Casualty Care Research Program of the US Army Medical Research and Materiel Command (DM180044). RSS is also funded by the Royal College of Surgeons of Edinburgh and Orthopaedic Research UK. JMW has received funding from the Royal College of Surgeons of England and Rosetrees Trust. For the remaining authors, none were declared.

  • Competing interests None declared.

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

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.