Avino A J, Oldenburg W A, Gloviczki P, Miller V M, Burgart L J, Atkinson E J
Department of General Surgery, University of Florida, USA.
J Vasc Surg. 1995 Sep;22(3):271-7; discussion 278-9. doi: 10.1016/s0741-5214(95)70141-9.
No single method has been identified that accurately and reliably detects patients with impending bowel infarction during aortic reconstruction. Serial sampling of blood gas from the inferior mesenteric vein (IMV) for detecting colonic ischemia was compared with two previously described techniques: laser Doppler flowmetry (LDF) and photoplethysmography.
Nine dogs underwent induced partial colonic ischemia followed by complete ischemia. Serial IMV blood gas measurements were obtained at four intervals: baseline, partial ischemia, complete ischemia, and reperfusion. Simultaneous direct colon wall LDF and PPG measurements also were obtained.
Changes in pH, Po2, O2 saturation, and Pco2 demonstrated progressive acidosis, hypoxemia, and hypercapnia in association with progressive arterial occlusion and a reversal of these trends toward baseline after restoration of flow. The absence of a pulsatile photoplethysmography tracing and oxygen saturation less than 90% were predictive of altered perfusion but could not differentiate partial from complete ischemia. Although the differences in mean LDF values were statistically different during ischemia and reperfusion, there was considerable variability between each measurement.
Analysis of blood gas from the IMV and pulse oximetry are useful techniques for detecting colonic ischemia, but only the former can distinguish partial from complete ischemia. The variability in colonic measurements with LDF limits its usefulness for detecting levels of colonic perfusion.
在主动脉重建过程中，尚未找到一种能准确可靠地检测出即将发生肠梗死患者的单一方法。将通过肠系膜下静脉（IMV）进行血气连续采样以检测结肠缺血的方法，与之前描述的两种技术：激光多普勒血流仪（LDF）和光电容积描记法进行比较。
对9只犬进行诱导性部分结肠缺血，随后进行完全缺血。在四个时间点进行IMV血气连续测量：基线、部分缺血、完全缺血和再灌注。同时还进行直接结肠壁LDF和PPG测量。
pH值、氧分压（Po2）、氧饱和度和二氧化碳分压（Pco2）的变化显示，随着动脉逐渐闭塞，出现进行性酸中毒、低氧血症和高碳酸血症，血流恢复后这些趋势逆转至基线水平。无搏动性光电容积描记图和氧饱和度低于90%可预测灌注改变，但无法区分部分缺血和完全缺血。虽然缺血和再灌注期间平均LDF值的差异有统计学意义，但每次测量之间存在相当大的变异性。
分析IMV血气和脉搏血氧饱和度测定是检测结肠缺血的有用技术，但只有前者能区分部分缺血和完全缺血。LDF测量结肠的变异性限制了其在检测结肠灌注水平方面的应用。
