Neuroanesthesia Notes

Cerebral Salt Wasting Syndrome
triad: hypoNa, volume contraction (low CVP), and high urine Na
a/w SAH –>bnp –>salt waste

SIADH is your differential, but SIADH is 2/2 renal retention of free water, so 24hr urine Na is normal in SIADH, normal CVP

DI and primary hyperaldosteronism –> elevated Na

Ref. Miller 8th ed p 2177

Intracranial HTN >15mmHg

-stimulation of peripheral nerves
-ascends ipsilateral dorsal column
-recorded on c/l somatosensory cortex

Hyperventilation lowers ICP
-reduces CBV and CBF
-duration wanes in 6-10hrs
-CBF decreases 2% for every mmHg decrease in PaCO2
-1ml/100g/min CBF increase per 1mmHg increase in Paco2 so since normal CBF is 50ml/100g/min then this is a 2% change