Webb A R, Barclay S A, Bennett E D
Intensive Therapy Unit, St. George's Hospital, London, UK.
Intensive Care Med. 1989;15(2):116-20. doi: 10.1007/BF00295988.
The rational choice of a plasma substitute for states of hypovolaemia depends partly on its colloid osmotic pressure (COP). We have measured the COP of 108 samples of plasma substitute across selectively permeable membranes which retain molecules greater than 10,000 dalton (COP10) and 50,000 dalton (COP50) the ratio COP50/COP10 providing a potential index of diffusibility of the smaller molecules across capillary membranes. 6% Hespan solution showed a particularly favourable COP50/COP10 ratio at 0.58 indicating a potential for good retention in the circulation whilst 3.5% Haemaccel showed a COP50/COP10 ratio of 0.18 indicating a potential for marked transcapillary diffusion, especially in states of capillary leak. In patients with normal capillary permeability both Gelofusine and Dextran 110 are likely to show adequate retention in the circulation with a COP50/COP10 ratio of 0.37 and 0.39 respectively. These are comparable to the retention of 4.5% human albumin (0.36) but all of the plasma substitutes tested, with the exception of Haemaccel, provided a higher COP across both membranes than 4.5% human albumin solution. An in vivo comparison of these plasma substitutes is required to confirm the advantages of macromolecular colloids in states of capillary leak.
对于低血容量状态，血浆代用品的合理选择部分取决于其胶体渗透压（COP）。我们已测量了108份血浆代用品样本透过选择性渗透膜的COP，这些膜能保留分子量大于10,000道尔顿的分子（COP10）和50,000道尔顿的分子（COP50），COP50/COP10的比值可作为较小分子跨毛细血管膜扩散性的潜在指标。6%贺斯溶液的COP50/COP10比值特别有利，为0.58，表明其在循环中具有良好的保留潜力；而3.5%血代的COP50/COP10比值为0.18，表明其有明显的跨毛细血管扩散潜力，尤其是在毛细血管渗漏状态下。在毛细血管通透性正常的患者中，佳乐施和右旋糖酐110的COP50/COP10比值分别为0.37和0.39，可能在循环中表现出足够的保留能力。这些与4.5%人白蛋白的保留能力（0.36）相当，但除血代外，所有测试的血浆代用品在两种膜上的COP均高于4.5%人白蛋白溶液。需要对这些血浆代用品进行体内比较，以证实大分子胶体在毛细血管渗漏状态下的优势。
