Noddeland H, Aukland K, Nicolaysen G
Acta Physiol Scand. 1981 Dec;113(4):447-54. doi: 10.1111/j.1748-1716.1981.tb06921.x.
Several theories could explain the slow rate of edema formation in the feet of sitting or standing man. One possible mechanism is a rise in local plasma colloid osmotic pressure (pi p). We measured pi p in blood from superficial veins of warm and cold feet during orthostasis. The difference in venous pi p between the foot and the arm averaged 12.8 mmHg (range 9.4-16.1 mmHg) in subjects sitting in a cold room. Hemoconcentration was also reflected as increased hematocrit. These findings support the view that a local increase of pi p in foot capillaries contributes considerably to edema prevention during orthostasis.
有几种理论可以解释久坐或站立的人足部水肿形成速度缓慢的现象。一种可能的机制是局部血浆胶体渗透压（πp）升高。我们在直立状态下测量了温暖和寒冷足部浅表静脉血中的πp。在寒冷房间里坐着的受试者中，足部与手臂之间的静脉πp差异平均为12.8 mmHg（范围为9.4 - 16.1 mmHg）。血液浓缩也表现为血细胞比容增加。这些发现支持了这样一种观点，即足部毛细血管中πp的局部升高在很大程度上有助于预防直立状态下的水肿。
