Peyton P J, Fortuin M, Robinson G J B, Stuart-Andrews C, Pierce R, Thompson B R
Department of Anaesthesia, Austin Hospital, Melborne, Australia.
Anaesthesia. 2008 Apr;63(4):358-63. doi: 10.1111/j.1365-2044.2007.05355.x.
The rate of anaesthetic gas uptake from the breathing system has been extensively measured, but this does not reflect the true rate of early gas uptake by pulmonary blood, which drives inhalational induction of anaesthesia. In eight patients undergoing coronary bypass surgery, we measured the rate of alveolar-capillary uptake of anaesthetic gases up to 30 min following introduction of 0.5% sevoflurane and 33% nitrous oxide using the reverse Fick method, in which blood partial pressures were measured using a headspace equilibration technique. Simultaneous measurements of gas uptake from the breathing system were made by indirect calorimetry. Measured rates of sevoflurane and nitrous oxide uptake from the breathing system agreed well with previously described formulae when adjusted for inspired concentration. The time course of alveolar-capillary gas uptake followed a characteristic rising curve peaking at 3-4 min and then exponentially declining, and for nitrous oxide was significantly higher than previously estimated.
从呼吸系统摄取麻醉气体的速率已得到广泛测量，但这并不能反映肺血早期摄取气体的真实速率，而正是肺血摄取气体驱动了吸入麻醉诱导。在8例接受冠状动脉搭桥手术的患者中，我们采用反向菲克法测量了在引入0.5%七氟醚和33%氧化亚氮后30分钟内麻醉气体的肺泡-毛细血管摄取速率，其中使用顶空平衡技术测量血液分压。通过间接量热法同时测量从呼吸系统摄取的气体量。当根据吸入浓度进行调整时，从呼吸系统摄取七氟醚和氧化亚氮的测量速率与先前描述的公式吻合良好。肺泡-毛细血管气体摄取的时间过程呈现出特征性的上升曲线，在3 - 4分钟达到峰值，然后呈指数下降，并且氧化亚氮的摄取速率显著高于先前估计值。
