Williams E M, Sainsbury M C, Sutton L, Xiong L, Black A M, Whiteley J P, Gavaghan D J, Hahn C E
Nuffield Department of Anaesthetics, University of Oxford, Radcliffe Infirmary, UK.
Respir Physiol. 1998 Jul;113(1):47-56. doi: 10.1016/s0034-5687(98)00051-6.
The aim of this study was to discover if the forced inspired inert gas sinewave technique could be used to measure pulmonary blood flow, using nitrous oxide as the indicator gas, following inotropic stimulation of the heart by dobutamine, in the presence of a constant alveolar ventilation. Cardiac output (range 1-4.5 L min(-1)) was measured in six dogs by thermodilution and by calculation from the sinusoidal expired partial pressures of argon and nitrous oxide using: (i) analytical equations and a conventional continuous ventilation three-compartment lung model, which did not include recirculation; and (ii) a digital simulation tidal ventilation lung model (Gavaghan and Hahn, 1996. Respir. Physiol. 106, 209-221) which was adapted to include nitrous oxide mixed-venous recirculation from a combined single viscera compartment. The continuous ventilation model calculations always underestimated thermodilution cardiac output, with the bias error increasing to almost -1 L min(-1) at the longest forcing periods, 4-5 min. In contrast, the tidal ventilation model calculations were in close agreement to thermodilution cardiac output, with biases of -0.04 and -0.26 L min(-1) at forcing periods of 2 and 3 min, respectively.
本研究的目的是探讨在持续肺泡通气的情况下，使用氧化亚氮作为指示气体，在多巴酚丁胺对心脏进行变力刺激后，强制吸入惰性气体正弦波技术是否可用于测量肺血流量。通过热稀释法，并使用以下方法根据氩气和氧化亚氮的正弦呼出分压进行计算，对6只犬的心输出量（范围为1 - 4.5 L min⁻¹）进行了测量：(i) 解析方程和传统的持续通气三室肺模型，该模型不包括再循环；(ii) 一个数字模拟潮气通气肺模型（Gavaghan和Hahn，1996年。呼吸生理学。106，209 - 221），该模型经过调整以纳入来自单一内脏联合腔室的氧化亚氮混合静脉再循环。持续通气模型的计算结果总是低估热稀释法测得的心输出量，在最长的强制期（4 - 5分钟），偏差误差增加到近 -1 L min⁻¹。相比之下，潮气通气模型的计算结果与热稀释法测得的心输出量密切一致，在2分钟和3分钟的强制期，偏差分别为 -0.04和 -0.26 L min⁻¹。
