EFFECTS OF POSITIVE END-EXPIRATORY PRESSURE ON REGIONAL DISTRIBUTION OF TIDAL VOLUME AND RECRUITMENT IN ADULT-RESPIRATORY-DISTRESS-SYNDROME
EFFECTS OF POSITIVE END-EXPIRATORY PRESSURE ON REGIONAL DISTRIBUTION OF TIDAL VOLUME AND RECRUITMENT IN ADULT-RESPIRATORY-DISTRESS-SYNDROME
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DOI：
10.1164/ajrccm.151.6.7767524
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发表时间：
1995-06-01
影响因子：
24.7
通讯作者：
VALENZA, F
中科院分区：
文献类型：
--
作者：
GATTINONI, L;PELOSI, P;VALENZA, F
本文对8例成人呼吸窘迫综合征（ARDS）的镇静瘫痪患者进行了胸廓CT检查，观察其潮气量（VT）分布及恢复情况。取0、5、10、15和20 cm H2O呼气末正压（PEEP）和相应的吸气平台压（21 +/- 1.8、26 +/- 1.4、31 +/- 1.8、38 +/- 2.1和46 +/- 3.2 cm H2O[平均+/- SE]）时仰卧位CT切片，保持VT恒定。每个CT切片沿其腹背高度划分为10个等距间隔（水平）。V-i（insp）和V-i（exp）分别定义为吸气末和呼气末第i层（i = 1 ~ 10）的气体体积。在每个肺水平上计算以下变量：(1)CT切片潮气量（VTct）的分布，即VT在给定肺水平上膨胀的比例；(2)平台诱导和PEEP诱导的肺组织复吸，即分别在平台压和PEEP时肺组织塌陷的数量；(3)再打开-坍缩组织，即在平台压力下恢复膨胀而在PEEP时坍缩的肺组织的数量。从0 ~ 20 cm H2O，随着PEEP的增加，上层的VTct分布显著降低（p < 0.01），中层没有变化，下层的VTct分布显著升高（p < 0.01）。高原诱导的复吸由高到低呈递增趋势（p < 0.01），但在21 ~ 46 cm H2O的高原压力下无明显变化。从0 ~ 20 cm H2O，从上到下，peep诱导的募集显著增加（p < 0.01）。因此，与PEEP相比，再打开-塌陷组织明显减少（p < 0.01）。我们认为，PEEP使镇静瘫痪的ARDS患者的气体分布更加均匀，使上层伸展，下层聚集。PEEP减少再打开-塌陷组织，保持平台压力招募的组织打开。
The distribution of tidal volume (VT) and recruitment was investigated by chest computed tomography (CT in eight sedated-paralyzed patients with the adult respiratory distress syndrome (ARDS). A CT section was obtained in the supine position at 0, 5, 10, 15, and 20 cm H2O positive end-expiratory pressure (PEEP) and at the corresponding inspiratory plateau pressure (21 +/- 1.8, 26 +/- 1.4, 31 +/- 1.8, 38 +/- 2.1, and 46 +/- 3.2 cm H2O [mean +/- SE]), keeping VT constant. Each CT section was divided along its ventral-dorsal height into 10 equally spaced intervals (levels). V-i(insp) and V-i(exp) were defined as the gas volume for level i(i = 1 to 10) at end-inspiration and at end-expiration, respectively. The following variables were computed at each lung level: (1) distribution of CT section tidal volume (VTct), i.e., the fraction of VT that inflates a given lung level; (2) the plateau-induced and PEEP-induced recruitment, i.e, the amount of lung tissue previously collapsed that inflates at plateau pressure and at PEEP, respectively; (3)the reopening-collapsing tissue, i.e., the amount of lung tissue that regains inflation at plateau pressure and collapses at PEEP. With increasing PEEP from 0 to 20 cm H2O, the VTct distribution decreased significantly (p < 0.01) in the upper levels, did not change in the middle levels, and increased significantly (p < 0.01) in the lower levels. The plateau-induced recruitment increased from upper to lower levels (p < 0.01) but was similar at plateau pressures from 21 to 46 cm H2O. PEEP-induced recruitment significantly increased (p < 0.01) from 0 to 20 cm H2O and from upper to lower levels. Consequently, the reopening-collapsing tissue decreased significantly (p < 0.01) with PEEP. We conclude that (PEEP makes the gas distribution more homogeneous in sedated-paralyzed ARDS patients, stretching the upper levels and recruiting the lower ones. PEEP reduces the reopening-collapsing tissue, keeping open the tissue recruited by plateau pressure.