Gravitational Ischemia in the Brain—May Contribute to Delirium and Mortality in the Intensive Care Unit
Highlights
- •Gravitational ischemia in the brain results from the mass effect of one part of the brain upon another in a gravitational field;
- •The finding that hypoactive delirium was more associated with mortality was consistent with hypoactive patients spending more time in a single body position;
- •Decreased arterial CO2 in the brain causes vasoconstriction, which reduces blood flow and worsens ischemia in medullary autonomic nuclei.
- •Brainstem focal ischemia may result in the initiation of intense autonomic discharges, which can occasionally be fatal.
- •Abnormal neural discharge to the heart via dorsal motor nucleus of vagus nerve would result in arrhythmias and sudden death.