Summary of Narrative Review on Traumatic Cardiac Arrest (TCA)

The treatment of traumatic cardiac arrest (TCA) has evolved significantly over recent decades, shifting from being seen as futile to a more promising intervention. This shift is attributed to a deeper understanding of TCA pathophysiology, distinct classification of TCA entities, updated guidelines, and advancements in diagnostic and therapeutic techniques such as point-of-care ultrasound (POCUS). Despite high overall mortality, outcomes in certain subgroups have improved.

A Swedish study involving nearly 300 adult TCAs highlighted that these patients are typically young (average age ~40 years), predominantly male (~80%), and mostly healthy before the incident. The study underscores the significant loss of productive life years and potential for organ donation in unsalvageable cases. The epidemiology of TCA varies globally, with firearm prevalence in the US notably influencing TCA demographics compared to Europe.

TCA causes are divided into potentially reversible (e.g., hemorrhage, tension pneumothorax, cardiac tamponade) and non-reversible (e.g., extensive organ damage). The H.O.T.T. acronym (Hypovolemia, Oxygenation impairment, Tension pneumothorax, Tamponade) aids in remembering reversible causes. Managing TCA focuses on rapidly addressing these reversible causes, although a universal approach is yet to be established.

Survival rates for TCA vary widely due to differences in study populations. Selected studies report survival rates from 4% to 40%, with better outcomes in patients resuscitated pre-hospital. Military data show varying survival, with some reporting 0% and others up to 11%. Factors improving outcomes include younger age, female sex, lower injury severity, and rapid intervention for reversible causes.

Diagnostic Challenges
Distinguishing true TCA from peri-arrest states like pseudo-PEA (where some blood flow exists despite absent palpable pulse) is critical. POCUS helps in identifying cardiac motion, crucial for prognosis. Absence of cardiac motion on POCUS is associated with extremely poor outcomes, guiding decisions on resuscitation continuation.

The traditional ABCD approach is modified for TCA, prioritizing simultaneous treatment of H.O.T.T. causes. Key therapeutic interventions include:

  • Airway: Emphasize creating a patent airway initially rather than securing it.
  • Breathing: Address tension pneumothorax and oxygenation issues promptly.
  • Circulation: Assume hypovolemia until proven otherwise and manage hemorrhage aggressively.
  • Disability: Manage associated injuries like traumatic brain injury and spinal cord injuries with appropriate prioritization.

Cardiac Rhythms and Compressions
Shockable rhythms are rare but associated with better outcomes. The role of chest compressions in hypovolemic TCA is controversial, with some guidelines deprioritizing them to focus on treating reversible causes.

Cardiac Injuries
Certain cardiac injuries like tamponade from stab wounds have better outcomes with immediate interventions like resuscitative thoracotomy. Cardiac contusions and electrotrauma-induced arrests follow standard ALS guidelines but need tailored resuscitation approaches.

Guidelines and Adrenaline Use
Guidelines for TCA resuscitation are based on expert opinions and retrospective studies, leading to variability. Current guidelines suggest withholding or terminating resuscitation based on specific criteria. The use of adrenaline in TCA is debated, with some studies indicating better outcomes with less or no adrenaline.

The paradigm shift in TCA treatment underscores the importance of rapidly addressing reversible causes to improve outcomes. Further research is necessary to enhance the prognosis for this often young and previously healthy patient population.