Fein A, Grossman R F, Jones J G, Goodman P C, Murray J F
Circulation. 1979 Nov;60(5):1156-60. doi: 10.1161/01.cir.60.5.1156.
To evaluate the clinical usefulness of measuring transthoracic electrical impedance in patients with pulmonary edema, we studied 27 normal subjects and 33 patients. In normal subjects, impedance increased when body position changed from supine to standing (p less than 0.01) and when lung volume increased from residual volume to total lung capacity (p less than 0.01). Impedance values vari7 omega) when measured hourly without removing the electrodes. In only five of 11 patients with clinically severe pulmonary edema and five of eight with radiologically severe pulmonary edema were impedance values outside the normal range. Changes in impedance values correlated with changes in clinical and radiographic indexes of pulmonary edema. We conclude that (1) single measurements of impedance are useless in diagnosing pulmonary edema, and (2) impedance changes as predicted as pulmonary edema increases and decreases, and these changes are readily detected by simpler methods of evaluation.
为评估测量经胸电阻抗在肺水肿患者中的临床应用价值，我们研究了27名正常受试者和33名患者。在正常受试者中，当体位从仰卧位变为站立位时（p<0.01）以及肺容积从残气量增加到肺总量时（p<0.01），电阻抗增加。在不取下电极的情况下每小时测量时，电阻抗值变化7欧姆。在11例临床重度肺水肿患者中只有5例以及8例放射学重度肺水肿患者中只有5例电阻抗值超出正常范围。电阻抗值的变化与肺水肿的临床和影像学指标的变化相关。我们得出结论：（1）单次测量电阻抗对诊断肺水肿无用；（2）随着肺水肿的加重和减轻，电阻抗按预期发生变化，并且这些变化可通过更简单的评估方法轻易检测到。
