systemic effect of inhalational anesthetic : CNS

• dose dependent reduction in cerebral metabolic rate(CMR) and Cerebral oxygen consumption(CMO), isoflurane and Sevo can decrease upto 50%
• all increases cerebral blood flow and hence ICT. order of vasodilation effect: halothane>desflurane=isoflurane>sevoflurane

due to more favourable effects on cerebral hemodynamics, better preservation of autoregulation, equivalent reduction in CMR,  smoother recovery. Sevo is agent of choice in neuro surgery

neurotoxicity and neuroprotection: in animal study,cognitive impairment in life if introduced at very young age. however human study inconclusive

• Direct hepatocellular damage seen with halothane(theory:iso and des)
• all causes liver damage to some degree decreasing blood flow to liver
• least direct damage seen with sevoflurane
• max with halothane

• All agent depress RFT by decreasing Renal blood flow.
• direct renal toxicity d/t fluoride (fluorinated to decrease their flammability)
• Vasopressin resistant polyuric renal failure 
• renal threshold for fluoride toxicity 50 micro mole

• N2O interacts with vitB12 
• inhibits enzyme methionine synthetase and reduces production of thymidate and DNA 
• causes megaloblastic anemia , aplastic anemia and homocystinuria

N2O inhibiting thymidylate production impair mylein production causing subacute degeneration of SC

• all are centrally acting muscle relaxant exceptN2O..
• maximum relaxation seen with desflurane

seen in animal study not in human , N2O

• current days agents : noninflammable 
• in past : ether and cyclopropane

not good analgesic except N2O and xenon

• Trielene : can produce dichloroacetyline (neurotoxic), phosgene gas(ARDS)
• Sevoflurane: toxic compound c/a compound A
• Desflurane: produce Carbonmonoxide with dessicated sodalime and barylime
• Sevoflurane : hydrogen fluoride which burns respiratory mucosa

• maximum caused by N2O,
• solution is use of closed circuit and avoid N2O as much as possible

uterine relaxants

except N2O all agents are good amnesic agent