EFFECTS OF EMBOLUS SIZE ON HEMODYNAMICS AND GAS-EXCHANGE IN CANINE EMBOLIC PULMONARY-HYPERTENSION
EFFECTS OF EMBOLUS SIZE ON HEMODYNAMICS AND GAS-EXCHANGE IN CANINE EMBOLIC PULMONARY-HYPERTENSION
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DOI：
10.1152/jappl.1990.69.6.2254
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发表时间：
1990-12-01
影响因子：
3.3
通讯作者：
NAEIJE, R
中科院分区：
文献类型：
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作者：
DELCROIX, M;MELOT, C;NAEIJE, R
我们在12只完整麻醉犬上观察了不同大小的玻璃微珠栓塞术对肺血流动力学和气体交换的影响。用多点肺动脉压(PPA)/心输出量(Q)曲线图评价给药前和给药后60min，给予足量100mU/m和1000mU/m玻璃微珠至基础水平的PPA和5 mg/kg肼后20min。在每个实验条件下，使用多次惰性气体消除技术来评估气体交换。栓塞术增加了线性PPA/Q图的外推压力截距(增加了6 mm Hg)和斜率(增加了5 mm Hg.1(-1)·min·m2)，伴随着80%的血管造影肺血管阻塞。这些变化在两个亚组的狗中没有显著差异。而动脉血氧分压在100mU-m后下降最明显，而动脉血氧分压在1000mU-m后升高最明显。两种小球的大小均使通气量(VA)/灌注量(Q)的分布变差，形成高VA/Q和低VA/Q的肺单位。只有100MU/m的小球产生分流。只有1000亩米的珠子产生了高VA/Q模式，并增加了惰性气体死区。在100亩/米的地块上，肼丙嗪增加了PPA/Q地块的分流，降低了坡度，而在1000亩/米的地块上没有影响。我们的结论是，在栓塞性肺动脉高压中，PPA/Q特征不受栓子大小为1,000微米的影响。然而，气体交换受到不同的影响，最小的栓子后分流增加，最大的栓子后VA/Q较高。最小栓子后的肺动脉高压可部分逆转，但这会进一步增加分流。
We examined the effects of different-sized glass-bead embolization on pulmonary hemodynamics and gas exchange in 12 intact anesthetized dogs. Pulmonary hemodynamics were evaluated by multipoint pulmonary arterial pressure (Ppa)/cardiac output (Q) plots before and 60 min after sufficient amounts of 100-mu-m (n = 6 dogs) or 1,000-mu-m (n = 6 dogs) glass beads to triple baseline Ppa were given and again 20 min after 5 mg/kg hydralazine in all the animals. Gas exchange was assessed using the multiple inert gas elimination technique in each of these experimental conditions. Embolization increased both the extrapolated pressure intercepts (by 6 mmHg) and the slopes (by 5 mmHg.1(-1).min.m2) of the linear Ppa/Q plots, together with an 80% angiographic pulmonary vascular obstruction. These changes were not significantly different in the two subgroups of dogs. However, arterial PO2 was most decreased after the 100-mu-m beads, and arterial PO2 was most increased after the 1,000-mu-m beads. Both bead sizes deteriorated the distribution of ventilation (VA)/perfusion (Q) ratios, with development of lung units with higher as well as lower than normal VA/Q. Only 100-mu-m beads generated a shunt. Only 1,000-mu-m beads generated a high VA/Q mode and increased inert gas dead space. Hydralazine increased the shunt and decreased the slope of the Ppa/Q plots after 100-mu-m beads and had no effect after 1,000-mu-m beads. We conclude that in embolic pulmonary hypertension, Ppa/Q characteristics are unaffected by embolus size up to 1,000-mu-m. Gas exchange, however, is affected differently, with an increased shunt after the smallest emboli and higher VA/Q after the largest emboli. Pulmonary hypertension after the smallest emboli is partially reversible by hydralazine, but this further increases shunt.