Acetazolamide slows VA/Q matching after changes in regional blood flow.
Acetazolamide slows VA/Q matching after changes in regional blood flow.
复制标题
局部血流变化后，乙酰唑胺会减慢 VA/Q 匹配。
DOI：
10.1152/jappl.1995.78.4.1312
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Hlastala,MP
中科院分区：
文献类型：
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作者：
Swenson,ER;Graham,MM;Hlastala,MP
乙酰唑胺对碳酸酐酶（CA）的抑制增加了通气-灌注（VA/Q）异质性（E。R. Swenson，H. T. Robertson和M. P. Hlastala. J. Clin. Invest.九十二：702-709，1993），这可能是因为与局部通气和灌注的时间波动相匹配的VA/Q的CO2/H（+）依赖性机制的减慢。为了研究这一概念，我们施加突然的变化，局部灌注的肺叶或左主肺动脉闭塞（PAO）麻醉机械通气的狗之前和之后CA抑制（20毫克/公斤乙酰唑胺静脉注射）。在连续吸入81 mKr气体通气扫描和多种惰性气体消除技术期间，通过肺平面γ成像测量通气再分布率和VA/Q分布随灌注变化的变化。PAO 5 min导致局部Kr活性下降30 ± 5%（SD），半衰期（t1/2）为75 ± 10 s。随着闭塞的释放，计数恢复至基线，t12为79 +/- 12 s。乙酰唑胺增加了这些相应的t1/2值（161 +/- 16和180 +/- 17 s）。与这些动力学相一致，与单独使用肺叶PAO相比，使用肺叶PAO在2分钟时VA/Q失配更大，但在CA抑制10分钟时则不是如此。周期性肺叶PAO和释放（10个周期的1分钟闭塞和1分钟释放）造成更多的VA/Q异质性在CA抑制。动脉-肺泡惰性气体面积差在周期性PAO时从0.18上升到0.23（P < 0.05），在CA抑制后从0.24上升到0.48（P < 0.01）。（250字处删节）
Inhibition of carbonic anhydrase (CA) by acetazolamide increases ventilation-perfusion (VA/Q) heterogeneity (E. R. Swenson, H. T. Robertson, and M. P. Hlastala. J. Clin. Invest. 92: 702–709, 1993), possibly because of slowing of CO2/H(+)-dependent mechanisms of VA/Q matching with temporal fluctuations of regional ventilation and perfusion. To study this concept, we imposed abrupt changes in regional perfusion by lobar or left main pulmonary artery occlusions (PAOs) in anesthetized mechanically ventilated dogs before and after CA inhibition (20 mg/kg iv acetazolamide). The rate of ventilation redistribution and change in VA/Q distributions with changes in perfusion were measured by planar gamma imaging of the lungs during continuous inhalation of 81mKr gas ventilation scanning and the multiple inert-gas elimination technique. PAO for 5 min caused regional Kr activity to fall by 30 +/- 5% (SD) with a half time (t1/2) of 75 +/- 10 s. With release of the occlusion, counts returned to baseline with t1/2 of 79 +/- 12 s. Acetazolamide increased these respective t1/2 values (161 +/- 16 and 180 +/- 17 s). Consistent with these kinetics, VA/Q mismatch was greater with lobar PAO at 2 min but not at 10 min with CA inhibition compared with that caused by lobar PAO alone. Cyclical lobar PAO and release (10 cycles of 1-min occlusion and 1-min release) caused more VA/Q heterogeneity during CA inhibition. The arterial-to-alveolar inert-gas area difference rose minimally from 0.18 to 0.23 (P < 0.05) with cyclical PAO and from 0.24 to 0.48 (P < 0.01) after CA inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)