British journal of anaesthesia
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Randomized Controlled Trial Multicenter Study Clinical Trial
Fresh gas flow is not the only determinant of volatile agent consumption: a multi-centre study of low-flow anaesthesia.
Seven academic centres studied 302 patients, using desflurane, enflurane, halothane, or isoflurane using circle-systems and Dräger Julian anaesthetic machines, with fresh gas flows (V(F)) of 3, 1, and 0.5 litre min(-1). Volatile agent partial pressures in the breathing system were recorded and agent consumptions measured by weighing. ⋯ At V(F) that involves significant re-breathing, consumption of soluble agents depends only partially on V(F). These results can be explained using Mapleson's hydraulic analogue model.