Indirect estimate of perimicrovascular pressure rise in edema in isolated zone 1 lung.
Indirect estimate of perimicrovascular pressure rise in edema in isolated zone 1 lung.
复制标题
间接估计隔离区 1 肺水肿时微血管周围压力升高。
DOI：
10.1152/jappl.1988.65.1.337
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Staub,NC
中科院分区：
文献类型：
--
作者：
Tanita,T;Onizuka,M;Staub,NC
为了确定液体积聚对肺泡外微血管间质压的影响，我们测量了1区条件(25 cmH2O肺泡压，20或10 cmH2O血管压)下所有血管均填充自体血浆的狗肺叶的滤过率。在基线条件下，从正常的肺泡外含水量开始，随着水肿液的缓慢积累，滤过速率在1h内下降了约一半。我们在造成肺水肿(高达100%的肺重量增加)后重复每个实验。水肿状态下滤过的绝对值和时间进程与基线无差异，即水肿不影响滤过时间进程。为了计算每一次1-h滤过性研究中出现的肺泡外微血管周围压的最大初始和最大变化，我们首先假设Starling方程中的反射系数为0，然后从两个具有两个未知量的方程计算微血管周围压和滤过系数。10个叶的平均过滤系数为0.063 g/(min×cmH2O×100g湿重)，初始微血管周围压为3.9cmH2O，1h上升4~7cmH2O，最后对低蛋白灌流液进行检测，发现过滤速率较高。我们计算了总反射系数=0.44，初始微血管周围压下降到1.9 cmH2O，在水肿形成1小时后略有上升，2.2-6.6 cmH2O。
To determine how liquid accumulation affects extra-alveolar perimicrovascular interstitial pressure, we measured filtration rate under zone 1 conditions (25 cmH2O alveolar pressure, 20 or 10 cmH2O vascular pressure) in isolated dog lung lobes in which all vessels were filled with autologous plasma. In the base-line condition, starting with normal extra-alveolar water content, filtration rate decreased by about one-half over 1 h as edema liquid slowly accumulated. We repeated each experiment after inducing edema (up to 100% lung weight gain). The absolute values and time course of filtration in the edema condition did not differ from base-line, i.e., the edema did not affect the time course of filtration. To compute the maximal initial and maximal change in extra-alveolar perimicrovascular pressure that occurred over each 1-h filtration study, we first assumed that the reflection coefficient is 0 in the Starling equation, then calculated perimicrovascular pressure and filtration coefficient from two equations with two unknowns. The mean filtration coefficient in 10 lobes is 0.063 g/(min X cmH2O X 100 g wet wt), and the initial perimicrovascular pressure is 3.9 cmH2O, rising by 4-7 cmH2O at 1 h. Finally we tested low protein perfusates and found the filtration rate was higher. We calculated an overall reflection coefficient = 0.44, a decrease in the initial perimicrovascular pressure to 1.9 cmH2O and a slightly lower increase after 1 h of edema formation, 2.2-6.6 cmH2O.