Conventional BLS and ALS considerations

Priority should be given to managing the above emergencies before conventional CPR modalities (external chest compressions / defibrillation) are commenced as correcting the cause of the cardiac arrest will give the patient the best chance at survival. This will only change where there is enough resources available to allow these interventions to happen simultaneously. In out of hospital traumatic cardiac arrest, the patient can have pulseless electrical activity (PEA) where pathophysiological events such as hypovolaemia or cardiac tamponade restrict the ability of the cardiovascular system to generate a palpable output. Therefore, addressing these reversible causes is the key to enhancing survival.7

External chest compressions & ventilation

In traumatic cardiac arrest, cardiac compressions are unlikely to be as effective as in normovolaemic cardiac arrest. Therefore, commencement of external chest compressions takes less of a priority than treatment of reversible causes. The patient in cardiac arrest from a haemorrhaghic cause receives little benefit until a sufficient circulating volume of blood is returned.
Once an attempt has been made to restore circulating volume and other reversible causes corrected, commence external chest compressions at the following ratio:
No ETT/SGA
  • 30 compressions / 2 breaths.
  • Aim for 100-120 compressions per minute.
  • Depth of 5cm with full recoil of the chest.
  • Pause for ventilations.
ETT / SGA
  • 15 compressions to 1 ventilation.
  • Aim for 100-120 compressions per minute.
  • Depth of 5cm with full recoil of the chest.
  • No pause for ventilations.
  • 6-8 ventilations per minute.

Adrenaline

The use of adrenaline in TCA has little evidence for or against it. It is recommended that its use only be considered once haemorrhage control, restoration of circulating volume, airway opening and decompression (if appropriate) have been addressed. The recommended dose is 10mL of adrenaline 1:10,000 (1mg) IV/IO repeated every two cycles (4 minutely) until ROSC. In the post cardiac arrest phase, consideration may be given to the use of adrenaline or other vasoactive infusions to maintain adequate blood pressure.   

Defibrillation

Once reversible causes have been identified, routine cardiac arrest management principles including a cardiac rhythm check should be applied. The majority of patients in cardiac arrest from a traumatic cause are not in a shockable rhythm, therefore defibrillation is not a priority. Management of the likely cause of TCA must be addressed first prior to consideration of defibrillation. The only exception to this is in Commotio Cordis, where the direct impact to the precordium alters the electrical stability of the myocardium, leading to VF or VT. In this situation, standard ALS principles should be implemented without a delay including early defibrillation.

Reversible causes

Standard ALS principles maintain consideration of the reversible causes as the “Four H’s and Four T’s” in any patient presenting with cardiac arrest. This updated TCA protocol will identify and treat the majority of the standard reversible causes of cardiac arrest:
  • Hypoxaemia.
  • Hypovolaemia.
  • Tension Pneumothorax.
  • Tamponade.
  • Hyper/hypokalaemia and other metabolic disorders.
The exception is given to hypo/hyperthermia, toxins and thrombosis. These infrequent causes of TCA may be considered where a patient has not responded to other interventions.