Ooi R, Joshi P, Soni N
Magill Department of Anaesthetics, Westminster Hospital, London.
J R Soc Med. 1992 Sep;85(9):534-6. doi: 10.1177/014107689208500908.
Nitrous oxide administration via an oxygen facemask such as the Mary Catterall (MC) is an accepted technique for supplementing regional anaesthesia. This study assessed the range of nitrous oxide and oxygen concentrations delivered to the trachea using a mechanical lung model. The inspired concentrations of these two gases were determined by the total fresh gas inflow rates, their concentrations in the fresh gas mixture and the peak inspiratory flow rate of the analogue lung. A 1:1 nitrous oxide-oxygen mixture in the fresh gas with an inflow rate of 4-6 l/min is recommended to ensure adequate oxygen delivery into the trachea as well as achieving the therapeutic concentrations of nitrous oxide (20-30%).
通过诸如玛丽·卡特拉尔（MC）面罩等氧气面罩给予氧化亚氮是一种公认的辅助区域麻醉的技术。本研究使用机械肺模型评估了输送至气管的氧化亚氮和氧气浓度范围。这两种气体的吸入浓度由新鲜气体总流入速率、它们在新鲜气体混合物中的浓度以及模拟肺的吸气峰值流速决定。建议在新鲜气体中使用氧化亚氮与氧气1:1的混合物，流入速率为4 - 6升/分钟，以确保有足够的氧气输送至气管，并达到氧化亚氮的治疗浓度（20% - 30%）。
