The effect of passive tilting on microvascular parameters in the human calf: a strain gauge plethysmography study.
The effect of passive tilting on microvascular parameters in the human calf: a strain gauge plethysmography study.
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被动倾斜对人小腿微血管参数的影响：应变计体积描记法研究。
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
I. Gartside
中科院分区：
文献类型：
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作者：
J. Gamble;F. Christ;I. Gartside
1.静脉充血压的累积小步用于研究被动倾斜对依赖组织中血管参数的影响。使用该方案，我们无创评估了静脉压（Pv，est）、等容袖带压（Pv，i），这是必须超过的充血袖带压（Pcuff），以诱导液体过滤。我们还评估了微血管滤过能力（Kf），当Pcuff > Pv，i时，Kf是滤过率（Jv）和Pcuff之间的线性关系，是可用交换血管表面积和壁电导的乘积。2.受试者被动倾斜，使小腿水平的静脉压增加47.4 +/-2.4 mmHg（平均值+/-S.E.M.）。施加倾斜后，Pv，i值从20.6 +/-1.8增加至48.5 +/-3.8 mmHg。这种变化可能反映了微血管界面处的胶体渗透压增加，这是已知的响应于这种操作而发生的。3.在施加被动倾斜后，Kf的预倾斜值未发生变化，值分别为3.2 +/-0.4 x 10（-3）和3.6 +/-0.4 x 10（-3）ml min-1（100 ml-1）mmHg-1（n = 13）。4.这些结果支持以下观点：被动姿势变化会改变毛细血管前阻力，从而改变交换血管内的压力和流量特性，但不会改变小腿中可用于液体交换的表面积，这与先前使用单步静脉闭塞方案在依赖性人足中的发现相反。
1. Cumulative small steps in venous congestion pressure were used to study the effect of passive tilt on vascular parameters in dependent tissues. Using this protocol we have non‐invasively assessed venous pressure (Pv,est), isovolumetric cuff pressure (Pv,i), which is the congestion cuff pressure (Pcuff) that has to be exceeded to induce fluid filtration. We have also assessed microvascular filtration capacity (Kf), which is the linear relationship between filtration rate (Jv) and Pcuff, when Pcuff > Pv,i, and is the product of the available exchange vessel surface area and wall conductance. 2. Subjects were passively tilted to increase the venous pressure at the level of the calf by 47.4 +/‐ 2.4 mmHg (mean +/‐ S.E.M.). The value of Pv,i increased from 20.6 +/‐ 1.8 to 48.5 +/‐ 3.8 mmHg after the imposition of the tilt. This change may reflect the increased colloid osmotic pressure at the microvascular interface that is known to occur in response to this manoeuvre. 3. The pre‐tilt value of Kf did not change after the imposition of the passive tilt, the values being 3.2 +/‐ 0.4 x 10(‐3) and 3.6 +/‐ 0.4 x 10(‐3) ml min‐1 (100 ml‐1) mmHg‐1, respectively, (n = 13). 4. These results support the notion that passive postural change alters the pre‐capillary resistance, thereby altering the pressure and flow characteristics within the exchange vessels, but does not alter the surface area available for fluid exchange in the calf, contrary to previous findings in the dependent human foot using a single‐step venous occlusion protocol.