Capillary hemodynamics in hemorrhagic shock and reperfusion: in vivo and model analysis.
Capillary hemodynamics in hemorrhagic shock and reperfusion: in vivo and model analysis.
复制标题
失血性休克和再灌注中的毛细血管血流动力学：体内和模型分析。
DOI：
10.1152/ajpheart.1994.267.5.h1928
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Skalak,TC
中科院分区：
文献类型：
--
作者：
Mazzoni,MC;Warnke,KC;Arfors,KE;Skalak,TC
采用计算机网络模型和骨骼肌微循环血流量的活体测量，研究了失血性休克和再灌注低流量的机制，重点是毛细血管直径和白细胞流变学的潜在重要性。模型流量由网络压力梯度、全身红细胞压积和白细胞压积、白细胞胞质粘度和血管尺寸确定。麻醉家兔休克1小时（急性出血40%）后，血压下降45%，血液稀释，毛细血管直径下降21%。通过激光多普勒血流仪（LDF）和微球技术在腓肠肌中实验发现的45-50%的流量减少与模型流量预测相匹配，其中一半的近端毛细血管变窄。乳酸林格氏液（RL）再灌注仅部分恢复了对照LDF流量，而小体积高渗盐水-右旋糖酐的推注，随后RL给LDF流量完全恢复。该模型预测了中度血液稀释状态下的这些流量，并进一步认识到，只有当白细胞被激活时，低流量条件才会因白细胞而加剧，这通常是缺血/再灌注的并发症。
A computer network model and in vivo measurements of microcirculatory blood flow in skeletal muscle were used to study the mechanisms responsible for low flow in hemorrhagic shock and reperfusion, with focus on the potential importance of capillary diameters and leukocyte rheology. Model flows were determined by the network pressure gradient, systemic hematocrit and leukocrit, leukocyte cytoplasmic viscosity, and vessel dimensions. After 1 h of shock (40% acute bleed) in anesthetized rabbits, pressure was reduced by 45%, hemodilution occurred, and capillary diameters decreased by 21%. The 45–50% flow reduction found experimentally in gastrocnemius muscle by laser Doppler flowmetry (LDF) and a microsphere technique matched model flow predictions with one-half of the proximal capillaries narrowed. Ringer-lactate (RL) reperfusion only partially restored control LDF flow, whereas a small-volume bolus of hypertonic saline-dextran followed by RL gave complete LDF flow recovery. The model predicted these flows for moderate hemodilution states, with the added insight that low-flow conditions are exacerbated by leukocytes only if they become activated, which is often a complication in ischemia/reperfusion.