Observational audit of sevoflurane consumption during paediatric anaesthesia

There is a recognition of the contribution to global warming from emissions of anaesthetic gases into the atmosphere. We audited sevoflurane use to help guide future initiatives to reduce consumption. We observed sevoflurane use during paediatric anaesthesia in a single operating theatre over eight weeks. We recorded demographics, timing of induction and maintenance of anaesthesia, type of circuit used and amount of liquid sevoflurane used (in mL). Ninety-four cases were available for analysis. Of these, 65 had gas inductions and 29 had intravenous (IV) inductions. The median sevoflurane use was 19 mL (interquartile range, IQR 13–24 mL). The median duration of cases was 50.5 min (IQR 35–78 min). The median sevoflurane consumption for cases with a gas induction was 22 mL (IQR 16–26 mL) and for those with an IV induction was 11 mL (IQR 7–17 mL; P < 0.00001). The duration of cases for the gas and IV induction cohorts were similar. During maintenance of anaesthesia, there was no difference between the IV and gas induction cohorts. There was little difference in sevoflurane use between the T-piece and circle system groups. Cases performed with gas inductions consumed twice the sevoflurane as those with IV inductions. Future interventions to reduce sevoflurane consumption should focus on this period.