Oxygen analyzers in anaesthesia: performance in a simulated clinical environment

Nine commercial oxygen analyzers were tested in a laboratory model stimulating clinical anaesthesia conditions. Fifteen test situations were used in order to study the effects of nitrous oxide, humidity, positive end-expiratory pressure, halothane, enflurane and isoflurane. Errors exceeding 8 vol% were not uncommon, the dominating source of error being humidity. Analyzers with efficient dehumidification of gases before analysis performed better than analyzers without this property.