Vajda K, Szabó Andrea, Boros M
Department of Surgery, County Teaching Hospital, Kecskemét, Hungary.
Eur Surg Res. 2004 Nov-Dec;36(6):338-44. doi: 10.1159/000081640.
In the event of a spatial or temporal microvascular perfusion heterogeneity conventional methods are often inadequate to describe the microcirculatory changes. Our aim was to use a new formula to characterize and compare the microcirculatory reactions in the mucosa and longitudinal muscle of the rat small intestine in response to hypertonic/hyperoncotic and normotonic resuscitation strategies.
Intravital videomicroscopy with an orthogonal polarization spectral (OPS) imaging technique was utilized. Microcirculatory variables were recorded during hemorrhagic shock (HS; 50 mm Hg mean arterial pressure for 60 min) and fluid replacement with 0.9% saline or with 7.2% saline containing 10% hydroxyethylstarch 200/0.5 (Osmohes; 4 ml/kg). Due to the temporal perfusion variability, microcirculatory changes were described using the calculation of the average red blood cell velocity (A-RBCV), while the spatial changes were calculated as a function of the size of the perfused capillary network.
During HS and the late phase of resuscitation, perfusion was characterized by capillary flow motion (i.e. variability in time) in the villi, and by spatial flow heterogeneity in the longitudinal muscle layer. The approximately 40% decrease in the calculated villus A-RBCV during HS was only partially affected by 0.9% saline, whereas Osmohes completely restored A-RBCV by increasing both the red blood cell velocity and the duration of high-flow periods at the onset of resuscitation in the villi. The approximately 60% reduction in A-RBCV in the muscle layer during HS was not followed by an appreciable recovery in either group, but Osmohes significantly increased A-RBCV in the late resuscitation phase.
The hypertonic/hyperoncotic solution induces a considerable microcirculatory improvement in two distinct layers of the small intestine after HS. This positive effect is related to the amelioration of the intestinal microcirculatory heterogeneity.
在出现空间或时间微血管灌注异质性的情况下,传统方法往往不足以描述微循环变化。我们的目的是使用一种新公式来表征和比较大鼠小肠黏膜和纵肌对高渗/高渗胶体和等渗复苏策略的微循环反应。
采用正交偏振光谱(OPS)成像技术进行活体视频显微镜检查。在失血性休克(HS;平均动脉压50mmHg,持续60分钟)期间以及用0.9%生理盐水或含10%羟乙基淀粉200/0.5的7.2%生理盐水(Osmohes;4ml/kg)进行液体复苏期间记录微循环变量。由于时间灌注变异性,使用平均红细胞速度(A-RBCV)的计算来描述微循环变化,而空间变化则根据灌注毛细血管网络的大小来计算。
在HS期间和复苏后期,绒毛的灌注特征为毛细血管血流运动(即时间变异性),纵肌层为空间血流异质性。HS期间计算得出的绒毛A-RBCV下降约40%,仅部分受到0.9%生理盐水的影响,而Osmohes通过增加绒毛复苏开始时的红细胞速度和高流量期的持续时间,完全恢复了A-RBCV。HS期间肌层A-RBCV下降约60%,两组均未出现明显恢复,但Osmohes在复苏后期显著增加了A-RBCV。
高渗/高渗胶体溶液在HS后可使小肠两个不同层的微循环得到显著改善。这种积极作用与肠道微循环异质性的改善有关。