Brain Injury Associated Shock: An Under-Recognized and Challenging Prehospital Phenomenon

Christopher Partyka; Alexander Alexiou; John Williams; Jimmy Bliss; Matthew Miller; Ian Ferguson

doi:10.1017/S1049023X24000359

Brain Injury Associated Shock: An Under-Recognized and Challenging Prehospital Phenomenon

Prehosp Disaster Med. 2024 Apr 29:1-6. doi: 10.1017/S1049023X24000359. Online ahead of print.

Authors

Christopher Partyka^{1

2

3}, Alexander Alexiou^{4

5

6}, John Williams⁷, Jimmy Bliss^{1

8}, Matthew Miller^{1

9

10}, Ian Ferguson^{1

8

11}

Affiliations

¹ Staff Specialist in Prehospital & Retrieval Medicine, NSW Ambulance, Aeromedical Operations, Bankstown Aerodrome, NSW, Australia.
² Staff Specialist in Emergency Medicine, Royal North Shore Hospital, St Leonards, NSW, Australia.
³ Clinical Lecturer and PhD Candidate, Faculty of Medicine and Health, University of Sydney, Sydney, Australia.
⁴ Consultant in Emergency Medicine, Royal London Hospital, London, England.
⁵ Consultant, Physician Response Unit, London's Air Ambulance, London, England.
⁶ Emeritus Prehospital Doctor, Essex & Herts Air Ambulance, England.
⁷ Critical Care Paramedic, NSW Ambulance, Aeromedical Operations, Bankstown Aerodrome, NSW, Australia.
⁸ Staff Specialist in Emergency Medicine, Liverpool Hospital, Liverpool, NSW, Australia.
⁹ Conjoint Lecturer, St George and Sutherland Clinical Campus, University of New South Wales, NSW, Australia.
¹⁰ Anesthetist, St George Hospital, Sydney, Australia.
¹¹ Conjoint Senior Lecturer, South West Sydney Clinical School, University of New South Wales, NSW, Australia.

PMID: 38680074
DOI: 10.1017/S1049023X24000359

Abstract

Objective: Hemodynamic collapse in multi-trauma patients with severe traumatic brain injury (TBI) poses both a diagnostic and therapeutic challenge for prehospital clinicians. Brain injury associated shock (BIAS), likely resulting from catecholamine storm, can cause both ventricular dysfunction and vasoplegia but may present clinically in a manner similar to hemorrhagic shock. Despite different treatment strategies, few studies exist describing this phenomenon in the early post-injury phase. This retrospective observational study aimed to describe the frequency of shock in isolated TBI in prehospital trauma patients and to compare their clinical characteristics to those patients with hemorrhagic shock and TBI without shock.

Methods: All prehospital trauma patients intubated by prehospital medical teams from New South Wales Ambulance Aeromedical Operations (NSWA-AO) with an initial Glasgow Coma Scale (GCS) of 12 or less were investigated. Shock was defined as a pre-intubation systolic blood pressure under 90mmHg and the administration of blood products or vasopressors. Injuries were classified from in-hospital computed tomography (CT) reports. From this, three study groups were derived: BIAS, hemorrhagic shock, and isolated TBI without shock. Descriptive statistics were then produced for clinical and treatment variables.

Results: Of 1,292 intubated patients, 423 had an initial GCS of 12 or less, 24 patients (5.7% of the original cohort) had shock with an isolated TBI, and 39 patients had hemorrhagic shock. The hemodynamic parameters were similar amongst these groups, including values of tachycardia, hypotension, and elevated shock index. Prehospital clinical interventions including blood transfusion and total fluids administered were also similar, suggesting they were indistinguishable to prehospital clinicians.

Conclusions: Hemodynamic compromise in the setting of isolated severe TBI is a rare clinical entity. Current prehospital physiological data available to clinicians do not allow for easy delineation between these patients from those with hemorrhagic shock.

Keywords: Emergency Medical Services; brain injury associated shock; shock; trauma; traumatic brain injury.