Primary mechanism responsible for cerebral protection effect of thiopentone is

C i.e. Decreased (lowered) cerebn metabolism Barbiturates (thiopental), primarily decreases cerebral metabolismQ resulting in a dose related depression of cevebral metabolic oxygen consumption (CMR02).Reduced CMRO2 causes progressive slowing of EEG, a reduction in rate of ATP consumption, cerebral vasoconstriction (reducing cerebral blood flow and intracranial tension) and protection from incomplete cerebral ischemiaQ. Thiopentone Sodium* Thiopentone is a yellow coloured powder used as 2.5 % solution at 5 mg/kg dose for smooth induction. It is ultrasho actingQ due to rapid redistributionQ. It is contraindicated in porphyria.Q.