Tel Aviv University, Tel Aviv 69978, Israel.
Colloids Surf B Biointerfaces. 2011 Mar;83(1):128-32. doi: 10.1016/j.colsurfb.2010.11.019. Epub 2010 Nov 18.
Hyperbaric oxygen (HBO) treatment defines the medical procedure when the patient inhales pure oxygen at elevated pressure conditions. Many diseases and all injuries are associated with a lack of oxygen in tissues, known as hypoxia. HBO provides an effective method for fast oxygen delivery in medical practice. The exact mechanism of the oxygen transport under HBO conditions is not fully identified. The objective of this article is to extend the colloid and surface science basis for the oxygen transport in HBO conditions beyond the molecular diffusion transport mechanism. At a pressure in the hyperbaric chamber of two atmospheres, the partial pressure of oxygen in the blood plasma increases 10 times. The sharp increase of oxygen concentration in the blood plasma creates a considerable concentration gradient between the oxygen dissolved in the plasma and in the tissue. The concentration gradient of oxygen as a non-electrolyte solute causes an osmotic flow of blood plasma with dissolved oxygen. In other words, the molecular diffusion transport of oxygen is supplemented by the convective diffusion raised due to the osmotic flow, accelerating the oxygen delivery from blood to tissue. A non steady state equation for non-electrolyte osmosis is solved asymptotically. The solution clearly demonstrates two modes of osmotic flow: normal osmosis, directed from lower to higher solute concentrations, and anomalous osmosis, directed from higher to lower solute concentrations. The fast delivery of oxygen from blood to tissue is explained on the basis of the strong molecular interaction between the oxygen and the tissue, causing an influx of oxygen into the tissue by convective diffusion in the anomalous osmosis process. The transport of the second gas, nitrogen, dissolved in the blood plasma, is also taken into the consideration. As the patient does not inhale nitrogen during HBO treatment, but exhales it along with oxygen and carbon dioxide, the concentration of nitrogen in blood plasma drops and the nitrogen concentration gradient becomes directed from blood to tissue. On the assumption of weak interaction between the inert nitrogen and the human tissue, normal osmosis for the nitrogen transport takes place. Thus, the directions of anomalous osmotic flow caused by the oxygen concentration gradient coincide with the directions of normal osmotic flow, caused by the nitrogen concentration gradient. This leads to the conclusion that the presence of nitrogen in the human body promotes the oxygen delivery under HBO conditions, rendering the overall success of the hyperbaric oxygen treatment procedure.
高压氧（HBO）治疗是指患者在高压条件下吸入纯氧的医疗程序。许多疾病和所有损伤都与组织缺氧（称为缺氧）有关。HBO 为医学实践中快速供氧提供了一种有效方法。高压氧条件下氧气输送的确切机制尚未完全确定。本文的目的是在胶体和表面科学的基础上，将氧气在 HBO 条件下的输送扩展到分子扩散输送机制之外。在高压舱的压力为两个大气压的情况下，血液中的氧分压增加 10 倍。血液中氧浓度的急剧增加在血浆中溶解的氧与组织中溶解的氧之间产生了相当大的浓度梯度。作为非电解质溶质的氧浓度梯度导致带有溶解氧的血浆的渗透流动。换句话说，氧气的分子扩散输送被由于渗透流动引起的对流扩散补充，从而加速氧气从血液向组织的输送。非稳态非电解质渗透的方程被渐近地求解。该解决方案清楚地表明了两种渗透流模式：从低浓度到高浓度的正常渗透，以及从高浓度到低浓度的反常渗透。基于氧气与组织之间的强分子相互作用，从血液到组织的氧气快速输送得到了解释，在反常渗透过程中，通过对流扩散将氧气吸入组织。还考虑了溶解在血液中的第二种气体，氮气的输送。由于患者在 HBO 治疗期间不吸入氮气，而是与氧气和二氧化碳一起呼出氮气，因此血液中氮气的浓度下降，氮气浓度梯度从血液指向组织。假设惰性氮气与人体组织之间的相互作用较弱，因此氮气的输送会发生正常渗透。因此，由氧浓度梯度引起的反常渗透流的方向与由氮浓度梯度引起的正常渗透流的方向一致。这得出结论，氮气在人体中的存在促进了 HBO 条件下的氧气输送，从而使高压氧治疗程序整体取得成功。
