Sevoflurane, sold under the brand name Sevorane, among others, 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.[2] While its offset may be faster than agents other than desflurane in a few circumstances, its offset is more often similar to that of the much older agent
isoflurane. While sevoflurane is only half as soluble as isoflurane in blood, the tissue blood partition coefficients of isoflurane and sevoflurane are quite similar. For example, in the muscle group: isoflurane 2.62 vs. sevoflurane 2.57. In the fat group: isoflurane 52 vs. sevoflurane 50. As a result, the longer the case, the more similar will be the emergence times for sevoflurane and isoflurane.[3][4][5]
It is one of the most commonly used
volatile anesthetic agents, particularly for outpatient anesthesia,[7] across all ages, as well as in veterinary medicine. Together with
desflurane, sevoflurane is replacing
isoflurane and
halothane in modern anesthesia practice. It is often administered in a mixture of
nitrous oxide and oxygen.
Physiological effects
Sevoflurane is a potent
vasodilator, as such it induces a dose dependent reduction in blood pressure and cardiac output. It is a
bronchodilator, however, in patients with pre-existing lung pathology it may precipitate coughing and
laryngospasm. It reduces the ventilatory response to
hypoxia and
hypercapnia and impedes hypoxic pulmonary vasoconstriction. Sevoflurane vasodilatory properties also cause it to increase intracranial pressure and cerebral blood flow. However, it reduces cerebral metabolic rate.
[8][9]
Adverse effects
Sevoflurane has an excellent safety record,[7] but is under review for potential
hepatotoxicity, and may accelerate Alzheimer's.[10] There were rare reports involving adults with symptoms similar to
halothanehepatotoxicity.[7] Sevoflurane is the preferred agent for mask induction due to its lesser irritation to
mucous membranes.
Sevoflurane is an inhaled anaesthetic that is often used to induction and maintenance of anaesthesia in children for surgery.[11] During the process of awakening from the medication, it has been associated with a high incidence (>30%) of agitation and
delirium in preschool children undergoing minor noninvasive surgery.[11] It is not clear if this can be prevented.[11]
Studies examining a current significant health concern, anesthetic-induced neurotoxicity (including with sevoflurane, and especially with children and infants) 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".[12]
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 (PANDA and GAS) 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.[13]
In 2021, researchers at Massachusetts General Hospital published in Communications Biology research that sevoflurane may accelerate existing Alzheimer's or existing tau protein to spread: "These data demonstrate anesthesia-associated tau spreading and its consequences. [...] This tau spreading could be prevented by inhibitors of tau phosphorylation or extracellular vesicle generation." According to Neuroscience News, "Their previous work showed that sevoflurane can cause a change (specifically, phosphorylation, or the addition of phosphate) to tau that leads to cognitive impairment in mice. Other researchers have also found that sevoflurane and certain other anesthetics may affect cognitive function."[10]
Additionally, there has been some investigation into potential correlation of sevoflurane use and renal damage (nephrotoxicity).[14] However, this should be subject to further investigation, as a recent study shows no correlation between sevoflurane use and renal damage as compared to other control anesthetic agents.[15]
Sevoflurane was discovered by Ross Terrell[26] 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 by Maruishi Pharmaceutical Co., Ltd. Osaka, Japan. The rights for sevoflurane worldwide were held by
AbbVie. It is now available as a
generic drug.
Sevoflurane will degrade into what is most commonly referred to as compound A (fluoromethyl 2,2-difluoro-1-(trifluoromethyl)vinyl ether) when in contact with CO2 absorbents, and this degradation tends to enhance with decreased fresh gas flow rates, increased temperatures, and increased sevoflurane concentration.[28] Compound A is what some believe is in correlation with renal damage.[29]
^World Health Organization (2023). The selection and use of essential medicines 2023: web annex A: World Health Organization model list of essential medicines: 23rd list (2023). Geneva: World Health Organization.
hdl:10665/371090. WHO/MHP/HPS/EML/2023.02.
^Vlisides P, Xie Z (2012). "Neurotoxicity of general anesthetics: an update". Current Pharmaceutical Design. 18 (38): 6232–6240.
doi:
10.2174/138161212803832344.
PMID22762477.
^Eger EI, Koblin DD, Bowland T, Ionescu P, Laster MJ, Fang Z, et al. (January 1997). "Nephrotoxicity of sevoflurane versus desflurane anesthesia in volunteers". Anesthesia and Analgesia. 84 (1): 160–168.
doi:
10.1213/00000539-199701000-00029.
PMID8989018.