Anesthesiology
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Randomized Controlled Trial
Caffeine Accelerates Emergence from Isoflurane Anesthesia in Humans: A Randomized, Double-blind, Crossover Study.
What did they do?
Using a randmoized, double-blind crossover study, Fong et al anaesthetized eight male volunteers twice with 1.2% isoflurane for 1 hour, after propofol induction. In the final 10 minutes subjects were randomized to IV caffeine or placebo. No opioids were administered.
Receiving IV caffeine hastened emergence by over 40%, as measured by BIS and psychomotor testing.
Return of gag reflex was used as the marker of emergence, although time to emergence was consistent with eye opening and BIS.
How much caffeine did they give?!?
15 mg/kg of caffeine citrate, equivalent to 7.5 mg/kg of base caffeine – the same caffeine as in two large cups of coffee for a 70 kg male.
Come on, surely this isn't that important?
Although the mean 7 min difference may not appear clinically significant, especially when using more modern volatiles, this study is a good proof of concept of how caffeine may be a useful clinical tool when faced with delayed emergence after anesthesia and for patients at greatest risk of persistent psychomotor depression post-anesthesia, such as the elderly.
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