Sevoflurane is a fluorinated compound commonly used as an inhalational agent and used in Sevoflurane anesthesia. Its brand names are Ultane and Sevorane.
Physical Properties of Sevoflurane :
• It is colorless liquid
• Odor is sweet so induction is smooth.
Anesthetic Properties of Sevoflurane :
Faster (B/G coefficient is 0.69), pleasant and smooth induction with no significant systemic toxicity makes the sevoflurane as agent of choice for induction, especially in children.
Systemic Effects of Sevoflurane :
Cardiovascular system: Cardiac output is minimally depressed.
Respiration: Effects similar to other agents i.e., depresses respiration and blunts ventilatory responses
Cerebral: increases intracranial tension.
Hepatic: It decreases portal blood flow but at the same time increases hepatic artery blood flow so hepatic blood flow is maintained.
Renal: Higher concentration can cause nephrotoxicity.
Metabolism of Sevoflurane :
It produces fluoride to renal threshold level but nephrotoxicity is not seen at clinical used concentrations (because of its rapid washout) but at higher concentration nephrotoxicity can occur.
Another toxic metabolic product compound A, an olefin is produced when sevoflurane is used with sodalime (especially at low fresh gas flows). So flow less than 2 litres/mm. are not recommended when sevoflurane is used in closed circuit.
Besides low flow other risk factors for production of compound A are:
1. Use of barylime.
2. High temperature.
3. Fresh absorbent.
4. High concentration of sevoflurane.