Brain Metabolism And Physiology

Brain metabolism and physiology: • In adult:O2 3.5 ml/100g/min& 5.5 mg/100g/min of glucose, peds 5.5 ml O2 • the autoregulation is abolished by trauma and hypoxia • CSF→ from the choroids plexus and absorbed by the arachnoid villi, volume 100-150 ml, rate of production and absorption 0.3-0.4 ml/min, with ↓ production by Lasix and acetazolamide • Enf ↑ production and ↑ resistance to absorption, Iso 0/ ↓ resistance • ICP N= 10 mmHg, ↑ ICP → ↓ CPP, and herniation • All volatile agents ↑ CBF with return to baseline in 3 hrs, with ↓ CMRO2 • All volatile agents and kitamine cause cerebral vasodilation, except N2O • N2O cause ↑ CBF w/out dilation, and no change in CMRO2 • All IV drugs cause ↓ CBF and ↓ CMRO2