RELATIONSHIP OF END-EXPIRATORY PRESSURE, LUNG-VOLUME, AND TC-99M-DTPA CLEARANCE
RELATIONSHIP OF END-EXPIRATORY PRESSURE, LUNG-VOLUME, AND TC-99M-DTPA CLEARANCE
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DOI：
10.1152/jappl.1987.63.4.1586
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发表时间：
1987-10-01
影响因子：
3.3
通讯作者：
MALIK, AB
中科院分区：
文献类型：
--
作者：
COOPER, JA;VANDERZEE, H;MALIK, AB
我们研究了呼气末正压（PEEP）和增加肺容量对雾化吸入99 mTc-DTPA（99 mTc-DTPA）肺清除率的剂量效应。肺放射性清除率表示为每分钟减少的百分比。基线清除率测定，同时麻醉绵羊（n = 20）与0 cmH 2 O呼气末压通气。在2.5、5、10、15或20 cmH 2 O PEEP通气期间重新测量清除率。进一步的研究显示，在0、2.5、5、10、15和20 cmH 2 O PEEP下测量的功能残气量（FRC）逐步增加（P < 0.05）。2.5cmH_2O PEEP时，FRC较基线时增加，但清除率与基线时无显著性差异（P> 0.05）。在5、10、15 cmH 2 O时，随着PEEP的增加，清除率逐渐增加（P < 0.05）。在15和20 cmH 2 O PEEP之间，尽管FRC增加，但清除率再次保持不变。雾化吸入99 mTc-DTPA的肺清除率对FRC和PEEP的增加呈S形反应，具有阈值效应和最大效应。这种关系与肺泡上皮通透性因肺膨胀而增加的假设最为一致。
We investigated the dose-response effect of positive end-expiratory pressure (PEEP) and increased lung volume on the pulmonary clearance rate of aerosolized technetium-99m-labeled diethylenetriaminepentaacetic acid (99mTc-DTPA). Clearance of lung radioactivity was expressed as percent decrease per minute. Base-line clearance was measured while anesthetized sheep (n = 20) were ventilated with 0 cmH2O end-expiratory pressure. Clearance was remeasured during ventilation at 2.5, 5, 10, 15, or 20 cmH2O PEEP. Further studies showed stepwise increases in functional residual capacity (FRC) (P < 0.05) measured at 0, 2.5, 5, 10, 15, and 20 cmH2O PEEP. At 2.5 cmH2O PEEP, the clearance rate was not different from that at base line (P < 0.05), although FRC was increased from base line. Clearance rate increased progressively with increasing PEEP at 5, 10, and 15 cmH2O (P < 0.05). Between 15 and 20 cmH2O PEEP, clearance rate was again unchanged, despite an increase in FRC. The pulmonary clearance of aerosolized 99mTc-DTPA shows a sigmoidal response to increasing FRC and PEEP, having both threshold and maximal effects. This relationship is most consistent with the hypothesis that alveolar epithelial permeability is increased by lung inflation.