Sevofluranepropane; synonym, fluoromethyl hexafluoroisopropyl ether),
is a sweet-smelling, nonflammable, highly fluorinated methyl isopropyl
ether used as an inhalational anaesthetic for induction and
maintenance of general anesthesia. After desflurane, it is the volatile
anesthetic with the fastest onset and offset.
It is one of the most commonly used volatile anesthetic agents, particularly
for outpatient anesthesia, and including in anesthesia of children and infants,
and in veterinary medicine. Together with desflurane, sevoflurane is
replacing isoflurane and halothane in modern anesthesiology. It is often
administered in a mixture of nitrous oxide and oxygen.
Sevoflurane "has an excellent safety record", but is under review for
potential neurotoxicity, especially relevant to administration in infants
and children, and rare reports similar to halothane hepatotoxicity. Sevoflurane
is the preferred agent for mask induction due to its lesser irritation
to mucous membranes. Sevoflurane was discovered by Ross
Terrell and independently by Bernard M Regan. A detailed report of its
development and properties appeared in 1975 in a paper authored by Richard
Wallin, Bernard Regan, Martha Napoli and Ivan Stern it was introduced into
clinical practice initially in Japan in 1990. The rights for sevoflurane in the
US and other countries were held by Abbott Laboratories; it is available as
a generic drug. Sevoflurane's name derives from the seven fluorine atoms in
its substituents, alongside a standard suffix for such agents.
Medical uses Sevoflurane is an inhaled anaesthetic
that is often used to put children asleep for surgery. During the process
of waking up from the medication, it has been known to cause agitation and
delirium. It is not clear if this can be prevented.
Adverse effects Sevoflurane raises intracranial pressure
and can cause respiratory depression. Studies examining a current significant
health concern, anesthetic-induced neurotoxicity are "fraught with
confounders, and many are underpowered statistically", and so are argued to
need "further data... to either support or refute the potential connection".
Concern regarding the safety of anaesthesia is especially acute with
regard to children and infants, where preclinical evidence from relevant
animal models suggest that common clinically important agents, including
sevoflurane, may be neurotoxic to the developing brain, and so cause
neurobehavioural abnormalities in the long term; two large-scale clinical
studies were ongoing as of 2010, in hope of supplying "significant [further]
information" on neurodevelopmental effects of general anaesthesia in
infants and young children, including where sevoflurane is used.
Pharmacology The exact mechanism of the action of
general anaesthetics have not been delineated. Sevoflurane is thought to
potentially acts as a positive allosteric modulator of the GABAA
receptor. However, it also acts as an NMDA receptor antagonist, potentiates
glycine receptor currents, and inhibits nACh and 5-HT3 receptor currents.
Physical properties = Bispectral index=
Sevoflurane has lower values of controversial bispectral index than
desflurane. References
Further reading Patel SS, Goa KL. "Sevoflurane. A review
of its pharmacodynamic and pharmacokinetic properties and its
clinical use in general anaesthesia". Drugs 51: 658–700.
doi:10.2165/00003495-199651040-00009. PMID 8706599. "Erratum". Drugs 52: 253.
August 1996. doi:10.1007/bf03257493. Wallin, Richard F., Regan, Bernard M.,
Napoli, Martha D., Stern, Ivan j.. "Sevoflurane: A New Inhalational
Anesthetic Agent". Anesthesia and Analgesia 54: 758–766.
doi:10.1213/00000539-197511000-00021. External links
"Propofol and Sevoflurane Anesthesia".