Adamicza A, Tutsek L, Nagy S
Institute of Experimental Surgery, Szent-Györgyi Albert Medical University, Szeged, Hungary.
Acta Chir Hung. 1997;36(1-4):1-3.
The purpose of our study was to examine the effect of sustained low-dose endotoxin infusion on changes in thoracic electrical impedances (Z0 at end-expiratory apnoea, Zmax at end-inspiration), Zmax-Z0, hematocrit (H) values, and extravascular lung water (EVLW) estimated with gravimetrical analysis (WW/DW) and the impedance method (dEVLWimp) in anesthetized dogs. To define the role of H in changes in the Z0 and Zmax, we applied splenectomy. To determine whether changes in respiration might be involved in changes in Z0 and Zmax, mechanically ventilated dogs were examined. During the infusion of endotoxin there was an increase in Z0, Zmax, H and the respiratory rate in the spontaneously breathing dogs. In splenectomized dogs both impedances slightly increased without any significant change in H. In the ventilated dogs Z0 and Zmax increased similarly, and H increased to a slightly lower level than in the spontaneously breathing dogs. In the ventilated-splenectomized dogs no changes were found in the impedances and in H. The EVLW values showed no serious edema in the endotoxemic groups. The results suggest that Z0 increased mainly in association with the increase in H. The Zmax-Z0 parameter proved to be a suitable parameter for demonstrating the changes in respiration.
我们研究的目的是检测持续低剂量内毒素输注对麻醉犬胸段电阻抗（呼气末屏气时的Z0、吸气末的Zmax）、Zmax-Z0、血细胞比容（H）值以及通过重量分析（WW/DW）和阻抗法（dEVLWimp）估算的血管外肺水（EVLW）的影响。为了确定H在Z0和Zmax变化中的作用，我们实施了脾切除术。为了确定呼吸变化是否可能与Z0和Zmax的变化有关，我们对机械通气的犬进行了检查。在内毒素输注期间，自主呼吸的犬的Z0、Zmax、H和呼吸频率均增加。在脾切除的犬中，两种阻抗略有增加，而H无任何显著变化。在通气的犬中，Z0和Zmax同样增加，且H增加到略低于自主呼吸犬的水平。在通气-脾切除的犬中，阻抗和H均未发现变化。内毒素血症组的EVLW值未显示严重水肿。结果表明，Z0的增加主要与H的增加有关。Zmax-Z0参数被证明是一个适用于显示呼吸变化的参数。
