Sevoflurane comparative studies

Isoflurane and sevoflurane have been compared in a randomized study in 180 patients undergoing knee arthroscopy (18). In those given sevoflurane there were significantly more respiratory and cardiovascular complications and increased nausea and vomiting. 

The effects of desflurane and sevoflurane on bronchial smooth muscle reactivity have been compared in a randomized study of 40 patients (36). Anesthesia was induced with thiopental, followed by muscle relaxation and ventilation. Airway pressures were recorded during administration of desflurane or sevoflurane at one minimal alveolar concentration (MAC). Airway resistance increased by 5% in the desflurane group and fell by 15% in the sevoflurane group. The increase in airways resistance was greater in smokers and with desflurane, but did not differ with sevoflurane. The result was a surprise, given that desflurane stimulates the sympathetic nervous system. Thiopental also increased airways resistance by 10%. The result is important, because induction of anesthesia can cause bronchospasm and desflurane can exacerbate this. 

Peripheral neuropathy has been reported in two healthy men anesthetized with 1.25 MAC sevoflurane at 21/minute fresh gas flow for 8 hours. Their average concentrations of compound A were 45 and 28 ppm. Both had had previous minor injuries in the regions in which the neuropathies were reported. The authors suggested that compound A, or other factors associated with sevoflurane anesthesia, may predispose patients to peripheral neuropathy. Both men were volunteers for earlier published studies comparing the nephrotoxic properties of sevoflurane and desflurane, sponsored by Baxter PPD, New Jersey, the manufacturer of desflurane, a rival inhalational anesthetic agent these reports need to be regarded with caution. 

Sevoflurane [(CF3)2CHOCH2F] was first used in Japan and introduced into American clinical practice in 1995. Sevoflurane is defluorinated to approximately the same extent as enflurane. In fact, initial studies reported that plasma levels of fluoride associated with sevoflurane anesthesia are comparable to those seen after enflurane administration [54, 55]. More recent studies, however, report that plasma fluoride concentrations often rise above 50 mM [56, 57]. Due to sevoflurane s low blood/gas solubility, only limited quantities build up during anesthesia and, as a result, fluoride levels fall very quickly after termination of anesthesia. In vivo, defluorination in rats is increased by pretreatment with phenobarbital [58]. 

Stoppe C, Fahlenkamp AV, Rex S, Veeck NC, Gozdowsky SC, Schalte G, et al. Feasibility and safety of xenon compared with sevoflurane anaesthesia in coronary surgical patients a randomized controlled pilot study. Br J Anaesth 2013 111 406-16. 

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