What is Cushing's Triad?
Cushing’s Triad is sign of increased intracranial pressure characterised by:
- Respiratory Depression.
Named after Harvey William Cushing, suggests increased pressure due to trauma, space occupying lesion or hydrocephalus. The appearance of the triad suggests of an emergency that may lead to death, and thus requires immediate intervention.
Physiology: The triad is a result of activation of both the sympathetic and parasympathetic responses. The sympathetic response causes constriction of arteries leading to hypertension. The baroreceptors detect the increased blood pressure causing the parasympathetic response to take over, leading to bradycardia via vagus nerve stimulation. The irregular breathing pattern is due to compression of the brain step due to the increased intracranial pressure or some endogenous stimulus. This whole process of what happens leading to the triad is also known as Cushing’s reflex.
- Medscape: Intracranial Pressure Monitoring (Retrieved 14 July 2014)