Bernard l'Ons^1
1NSWHP

Impact brain apnoea is defined by the cessation of breathing after traumatic brain injury, and is characterised by the patient appearing lifeless, pale, with no respiratory effort. It is distinct from airway obstruction that may occur during reduced levels of consciousness. 

The two immediate pathophysiological events that may occur following head injury are apnoea and massive sympathetic discharge . The apnoea leads to hypoxia and the sympathetic discharge leads to an increased cardiovascular demand for oxygen. This interplay results in cardiorespiritory collapse. 

 

IBA is thought to be exacerbated by alcohol. Lateral impact  to the head is reported to be an additional risk factor.