RT Book, Section A1 Goettel, Nicolai A2 Atchabahian, Arthur A2 Gupta, Ruchir SR Print(0) ID 57262024 T1 Chapter 101. Craniotomy T2 The Anesthesia Guide YR 2013 FD 2013 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-176049-2 LK accessanesthesiology.mhmedical.com/content.aspx?aid=57262024 RD 2024/03/29 AB Table Graphic Jump Location|Download (.pdf)|PrintCranial contentsSkull represents a closed, non-expandable unit containing three compartments (CBV, CSF, brain tissue) determining ICPAny increase in volume of one of the cranial compartments must be compensated by a decrease in volume of another to maintain the pressure equilibrium (Monro-Kellie doctrine)Small increases in intracranial volume will lead to large increases in ICP once this buffer mechanism is exhausted (Figure 101-1), compromising CBVBlood and cerebral vasculature (cerebral blood volume, CBV)Two carotid arteries (70% blood flow to the brain)Two vertebral arteries (30% blood flow to the brain)Arterial anastomosis through Willis circle and anastomosis with external carotid arteries through branches of facial and ophthalmic arteriesVenous return through cortical veins (superficial drainage), and basilar and ventricular veins (profound drainage) essentially into the IJ veinsCerebro-spinal fluid (CSF)Produced by choroid plexus, reabsorbed by granules of PacchioniTotal volume of CSF in the adult: 140–270 mLProduction of 0.2–0.7 mL/min or 600–700 mL/day