Validation of tonometric measurement of gut intramural pH during endotoxemia and mesenteric occlusion in pigs.
Validation of tonometric measurement of gut intramural pH during endotoxemia and mesenteric occlusion in pigs.
复制标题
DOI：
10.1152/ajpgi.1990.259.4.g519
复制
发表时间：
1990-10
期刊：
影响因子：
--
通讯作者：
J. Antonsson;C. Boyle;K. Kruithoff;H. Wang;E. Sacristán;H. R. Rothschild;M. Fink
中科院分区：
文献类型：
--
作者：
J. Antonsson;C. Boyle;K. Kruithoff;H. Wang;E. Sacristán;H. R. Rothschild;M. Fink
眼压测量是一种用于估计胃肠道壁内pH（pHi）的微创方法。通过使用Henderson-Hasselbalch方程和测量肠腔内硅橡胶球囊中所含盐水的动脉[HCO-3]和CO2张力（PCO 3）计算组织pH值。该方法的有效性取决于两个关键假设：1）眼压计球囊中生理盐水中的PCO 2与组织PCO 2相似，2）组织和动脉[HCO-3]相似。为了验证这种方法，回肠pHi直接测量微电极与pHi估计张力在四组麻醉猪进行了比较。I组（n = 4）为对照组。在II组（n = 4），肠组织酸中毒诱导的上级肠系膜动脉（SMA）的完全闭塞。在第III组（n = 5）中，通过SMA的部分闭塞诱导酸中毒。在IV组（n = 4）中，组织酸中毒由内毒素血症诱导。第I组和第IV组的直接测量和眼压测量之间的一致性非常好，第II组和第III组的一致性较差。在第II组和第IV组中，两种测量方法的加权平均相关系数（rw）分别为0.743和0.9447。第III组中个体动物的相关系数比其他组更易变，范围为0.547 - 0.990。用于测量GI pHi的眼压计方法在零流量条件下无效，并且在低流量条件下导致误差。然而，该方法在内毒素血症诱导的组织酸中毒的情况下是可靠的。
Tonometry is a minimally invasive method for estimating gastrointestinal intramural pH (pHi). Tissue pH is calculated by using the Henderson-Hasselbalch equation and measurements of arterial [HCO-3] and CO2 tension (PCO3) of saline contained in a Silastic balloon within the lumen of the gut. The validity of the method rests on two key assumptions: 1) PCO2 in saline in the tonometer balloon is similar to tissue PCO2 and 2) tissue and arterial [HCO-3] are similar. To validate this method, ileal pHi measured directly with a microelectrode was compared with pHi estimated tonometrically in four groups of anesthetized pigs. Group I (n = 4) were controls. In group II (n = 4), intestinal tissue acidosis was induced by total occlusion of the superior mesenteric artery (SMA). In group III (n = 5), acidosis was induced by partial occlusion of the SMA. In group IV (n = 4), tissue acidosis was induced by endotoxemia. Agreement was excellent between direct and tonometric measurements in groups I and IV and less good in groups II and III. Weighted mean correlation coefficients (rw) for the two measurement methods were 0.743 and 0.9447 in groups II and IV, respectively. Correlation coefficients for the individual animals in group III were more variable than the other groups and ranged from 0.547 to 0.990. The tonometric method for measuring GI pHi is invalid under conditions of zero flow and leads to error under conditions of low flow. However, the method is reliable in the setting of tissue acidosis induced by endotoxemia.