Abrams J H, Weber R E, Holmen K D
Department of Surgery, University of Minnesota, Minneapolis 55455.
Anesthesiology. 1989 Jan;70(1):134-8.
An endotracheal tube with a 5 mm diameter ultrasonic transducer incorporated into its distal end was inserted into the tracheas of six anesthetized dogs. The device provides for ultrasound measurement of aortic diameter and blood velocity in the ascending aorta to obtain cardiac outputs. Because measurements are made proximal to the origins of the aortic arch vessels, total cardiac output is obtained. Procedures for measurement of aortic diameter, aortic blood velocity, and cardiac output are discussed. The resulting data were used to empirically determine the angle of incidence of the ultrasound beam that gave the best least squares fit over a range of thermodilution cardiac outputs. For an angle of incidence of 62.3 degrees, the relationship between cardiac output determined by thermal dilution and by transtracheal Doppler was transtracheal Doppler cardiac output = -.69 + 1.19 thermal dilution cardiac output. R2 = .82. The results from this preliminary assessment of the feasibility of measuring cardiac output in dogs using transtracheal Doppler suggest that additional studies should be pursued. Additional issues that require investigation include confirmation of constancy of human anatomy and demonstration of lack of tracheal trauma from the Doppler equipped endotracheal tube.
将一根直径5毫米、在其远端装有超声换能器的气管内导管插入6只麻醉犬的气管。该装置可对升主动脉的主动脉直径和血流速度进行超声测量，以获得心输出量。由于测量是在主动脉弓血管起源的近端进行的，因此可获得总心输出量。文中讨论了测量主动脉直径、主动脉血流速度和心输出量的方法。所得数据用于根据经验确定在一系列热稀释心输出量范围内能给出最佳最小二乘拟合的超声束入射角。对于62.3度的入射角，经气管多普勒法测定的心输出量与热稀释法测定的心输出量之间的关系为：经气管多普勒心输出量 = -0.69 + 1.19×热稀释心输出量。R2 = 0.82。这项关于使用经气管多普勒法测量犬心输出量可行性的初步评估结果表明，应开展更多研究。需要调查的其他问题包括确认人体解剖结构的稳定性，以及证明配备多普勒的气管内导管不会造成气管损伤。
