Abraham P, Leftheriotis G, Desvaux B, Saumet M, Saumet J L
Laboratoire de Physiologie et d'Explorations Vasculaires, Centre Hospitalier Universitaire d'Angers, France.
Am J Physiol. 1994 Oct;267(4 Pt 2):H1337-40. doi: 10.1152/ajpheart.1994.267.4.H1337.
We used ultrasound to study venous return during heat stress. We measured venous cross-sectional area (CSA) and blood flow velocity (BFV) of nine femoral veins and nine saphenous veins. During heat stress, saphenous CSA increased from 4.7 +/- 2.6 mm2 (mean +/- SD) to 9.1 +/- 2.3 mm2 (P < 0.01), whereas femoral CSA was 22.7 +/- 9.5 mm2 at rest and 22.0 +/- 9.6 mm2 during heat stress (NS). Meanwhile, BFV increased from 0.06 +/- 0.02 to 0.30 +/- 0.10 m/s (P < 0.01) in the saphenous vein and from 0.14 +/- 0.08 to 0.38 +/- 0.23 m/s (P < 0.005) in the femoral vein. Maximal venous outflow (MVO) was the product of CSA and BFV. During heat stress, MVO showed an eightfold increase in the saphenous veins (from 22.7 +/- 18.2 to 180.7 +/- 86.7 ml/min) and a 2.5-fold increase in the femoral veins (from 143.4 +/- 52.9 to 354.0 +/- 126.9 ml/min). The results showed that one-half of the cutaneous blood flow increase during heat stress returned through the deep collecting veins in the lower limb. Thereafter, although there was no venodilation of deep veins compared with superficial veins, the deep veins remain the main pathway for the venous return during heat stress.
我们使用超声研究热应激期间的静脉回流。我们测量了九条股静脉和九条隐静脉的静脉横截面积（CSA）和血流速度（BFV）。在热应激期间，隐静脉CSA从4.7±2.6mm²（平均值±标准差）增加到9.1±2.3mm²（P<0.01），而股静脉CSA在静息时为22.7±9.5mm²，在热应激期间为22.0±9.6mm²（无显著性差异）。同时，隐静脉的BFV从0.06±0.02增加到0.30±0.10m/s（P<0.01），股静脉的BFV从0.14±0.08增加到0.38±0.23m/s（P<0.005）。最大静脉流出量（MVO）是CSA与BFV的乘积。在热应激期间，隐静脉的MVO增加了八倍（从22.7±18.2增加到180.7±86.7ml/min），股静脉的MVO增加了2.5倍（从143.4±52.9增加到354.0±126.9ml/min）。结果表明，热应激期间增加的皮肤血流量的一半通过下肢深集合静脉回流。此后，尽管与浅静脉相比深静脉没有静脉扩张，但深静脉仍然是热应激期间静脉回流的主要途径。
