[气管内吸引对压力控制或容量控制通气下机械通气患者气体交换和呼吸力学的影响]

[The effects of endotracheal suction on gas exchange and respiratory mechanics in mechanically ventilated patients under pressure-controlled or volume-controlled ventilation].

作者信息

Liu Xiao-wei, Liu Zhi

机构信息

Department of Emergency Medicine, The First Affiliated Hospital, China Medical University, Shenyang 110001, China.

出版信息

Zhonghua Jie He He Hu Xi Za Zhi. 2007 Oct;30(10):751-5.

PMID:18218205

Abstract

OBJECTIVE

To compare the effects of endotracheal suction on gas exchange and respiratory mechanics in mechanically ventilated patients receiving pressure-controlled ventilation (PCV) or volume-controlled ventilation (VCV).

METHODS

A randomized cross-over study was conducted. Twenty-three mechanically ventilated patients were randomly assigned to ventilation with either PCV or VCV at first, and then the other. Endotracheal suction was performed with an open suction system. Changes in gas exchange and respiratory mechanics after suctions under the two modes were compared.

RESULTS

With PCV, the tidal volume (VT) and the compliance were (6.60+/-1.95) ml/kg and (18+/-7) ml/cm H2O (1 cm H2O=0.098 kPa) respectively at 30 minutes after suction, as compared to (9.05+/-0.22) ml/kg and (24+/-6) ml/cm H2O respectively at baseline; the difference being significant (F=8.47, 8.01, all P<0.05). PaO2 and PaCO2 were (87+/-13) mm Hg (1 mm Hg=0.133 kPa) and (53+/-11) mm Hg respectively at 30 minutes after suction, as compared to (113+/-22) mm Hg and (41+/-10) mm Hg respectively at 0 minute; the difference being significant (F=6.18, 9.13, all P<0.05). With VCV, the compliance, the plateau pressure and the peak inspiratory pressure were (18+/-7) ml/cm H2O, (27+/-8) cm H2O and (33+/-8) cm H2O respectively at 30 minutes after suction, as compared to (23+/-7) ml/cm H2O, (22+/-5) cm H2O, and (27+/-8) cm H2O respectively at baseline; the difference being significant (F=6.83, 6.97, 7.08, all P<0.05). PaO2 and PaCO2 were (105+/-26) mm Hg and (38+/-11) mm Hg respectively at 30 minutes after suction, as compared to (109+/-21) mm Hg and (37+/-14) mm Hg respectively at 0 minute; but the difference was not significant (F=1.88, 1.32, all P>0.05). With PCV, the heart rate (HR) and the mean systemic arterial pressure (MAP) were (109+/-20) beats/min and (89+/-10) mm Hg respectively at 5 minutes after suction, as compared to (97+/-17) beats/min and (83+/-12) mm Hg respectively at baseline; the difference being significant (F=5.86, 9.49, all P<0.05). With VCV, HR and MAP were (110+/-17) beats/min and (87+/-11) mm Hg respectively at 5 minutes after suction, as compared to (96+/-17) beats/min and (79+/-11) mm Hg respectively at baseline; the difference being significant (F=7.33, 7.96, all P<0.05).

CONCLUSION

Endotracheal suction causes lung collapse leading to impairment of gas exchange and decreased compliance both under PCV and VCV, but the effect on gas exchange was more severe and persistent under PCV than under VCV.

摘要

目的

比较气管内吸引对接受压力控制通气（PCV）或容量控制通气（VCV）的机械通气患者气体交换和呼吸力学的影响。

方法

进行了一项随机交叉研究。23例机械通气患者首先随机分配接受PCV或VCV通气，然后再接受另一种通气。使用开放式吸引系统进行气管内吸引。比较两种模式下吸引后气体交换和呼吸力学的变化。

结果

在PCV模式下，吸引后30分钟时潮气量（VT）和顺应性分别为（6.60±1.95）ml/kg和（18±7）ml/cm H2O（1 cm H2O = 0.098 kPa），而基线时分别为（9.05±0.22）ml/kg和（24±6）ml/cm H2O；差异有统计学意义（F = 8.47，8.01，P均<0.05）。吸引后30分钟时PaO2和PaCO2分别为（87±13）mmHg（1 mmHg = 0.133 kPa）和（53±11）mmHg，而0分钟时分别为（113±22）mmHg和（41±10）mmHg；差异有统计学意义（F = 6.18，9.13，P均<0.05）。在VCV模式下，吸引后3０分钟时顺应性、平台压和吸气峰压分别为（18±7）ml/cm H2O、（27±8）cm H2O和（33±8）cm H2O，而基线时分别为（23±7）ml/cm H2O、（22±5）cm H2O和（27±8）cm H2O；差异有统计学意义（F = 6.83，6.97，7.08，P均<0.05）。吸引后30分钟时PaO2和PaCO2分别为（105±26）mmHg和（38±11）mmHg，而0分钟时分别为（109±21）mmHg和（37±14）mmHg；但差异无统计学意义（F = 1.88，1.32，P均>0.05）。在PCV模式下，吸引后5分钟时心率（HR）和平均体动脉压（MAP）分别为（109±20）次/分钟和（89±10）mmHg，而基线时分别为（97±17）次/分钟和（83±12）mmHg；差异有统计学意义（F = 5.86，9.49，P均<0.05）。在VCV模式下，吸引后5分钟时HR和MAP分别为（110±17）次/分钟和（87±11）mmHg，而基线时分别为（96±17）次/分钟和（79±11）mmHg；差异有统计学意义（F = 7.33，7.96，P均<０.05）。