Final answer:
The probable cause for the 56-year-old male being apneic and pulseless after a car crash is likely traumatic cardiac arrest. Immediate care with CPR and AED use is critical, and emergency services should be involved for advanced support.
Step-by-step explanation:
The probable cause of the man's condition could be traumatic cardiac arrest due to the accident. When a person is found to be apneic (not breathing) and pulseless, it suggests that the heart has stopped working, which is known as cardiac arrest. In the context of a car crash, even at low speed, the individual may have sustained a blunt force trauma to the chest, leading to a condition such as commotio cordis, where the impact causes a disruption of the heart's electrical system, possibly resulting in cardiac arrest.
Other potential causes include traumatic injury to other critical structures in the chest or preexisting medical conditions that could be exacerbated by the stress of the accident, such as a heart attack (myocardial infarction) or arrhythmia. Immediate care should focus on Cardiopulmonary Resuscitation (CPR) and using an Automated External Defibrillator (AED) if available, which are the primary treatments for sudden cardiac arrest.