Feigenwinter P, Pohle T H, Zbinden A M
Institute of Anaesthesiology and Intensive Care, University Hospital of Bern, Switzerland.
Eur J Anaesthesiol. 1996 Jan;13(1):73-80. doi: 10.1097/00003643-199601000-00013.
The majority of contemporary gas delivery modules, on anaesthetic workstations, are equipped with oxygen-nitrous oxide proportioning systems which should prevent the delivery of hypoxic gas mixtures. We investigated five modules, of two different types, using fresh gas flows ranging from 50 mL min-1 to 20 L min-1 with minimally acceptable proportions of oxygen and maximally acceptable proportions of nitrous oxide set at the flow control valves. The oxygen concentrations of the resulting gas mixtures were measured at the fresh gas outlet of the gas delivery modules. All the modules prevented the delivery of hypoxic fresh gas flows both under normal and abnormal working conditions (unequal supply of gas pressures). All systems showed increased O2 concentrations at fresh gas flows below 1 L min-1. The systems can be used with low flow anaesthesia techniques with one exception (Dameca) also with minimal flow techniques.
大多数当代麻醉工作站上的气体输送模块都配备了氧气-一氧化二氮配比系统，该系统应能防止输送低氧气体混合物。我们研究了两种不同类型的五个模块，使用的新鲜气体流量范围为50 mL/min至20 L/min，在流量控制阀处设定了最低可接受的氧气比例和最高可接受的一氧化二氮比例。在气体输送模块的新鲜气体出口处测量所得气体混合物的氧气浓度。所有模块在正常和异常工作条件下（气体压力供应不均）均能防止输送低氧新鲜气体流。所有系统在新鲜气体流量低于1 L/min时氧气浓度都会升高。这些系统可用于低流量麻醉技术，有一种情况除外（达美卡），也可用于最低流量技术。
