[早期急性呼吸窘迫综合征绵羊血管外肺水的变化]

[Change of extravascular lung water in sheep with early acute respiratory distress syndrome].

作者信息

Qiu Hai-bo, Sun Hui-Ming, Yang Yi, Xu Hong-yang, Chen Yong-ming

机构信息

Department of Critical Care Medicine, Zhong-Da Hospital and School of Clinical Medicine, Southeast University, Nanjing 210009, China.

出版信息

Zhonghua Jie He He Hu Xi Za Zhi. 2004 Aug;27(8):537-41.

PMID:15388003

Abstract

OBJECTIVE

To determine the change of extravascular lung water (EVLW) and the effect of positive end-expiratory pressure (PEEP) and cardiac output (CO) on EVLW in the sheep with early acute respiratory distress syndrome (ARDS).

METHODS

The sheep ARDS model was induced by infusion of endotoxin intravenously, and then divided into ARDS model group (n = 12), PEEP group (n = 21) and dobutamine group (n = 13). The PEEP group was further divided into three subgroups: PEEP 5 cm H(2)O (n = 7), 10 cm H(2)O (n = 8) and 15 cm H(2)O groups (n = 6). EVLW was measured by the single indicator thermodilution technique. The EVLW, hemodynamics and lung mechanics parameters were observed at 6 h after sheep ARDS model was induced, 2 h after mechanical ventilation with PEEP (5, 10, 15 cm H(2)O) respectively and 2 h after CO increase >/= 50% of the base value (induced by dobutamine infusion).

RESULTS

(1) When ARDS was induced in sheep, EVLW increased from (12.8 +/- 4.7) ml/kg to (18.1 +/- 7.1) ml/kg (P < 0.01), and EVLW had no significant change (P > 0.05) during the early phase of ARDS (6 h). PaO(2)/FiO(2) was (136.8 +/- 34.9) mm Hg at ARDS 0 h, which was higher than that before infusion of endotoxin [(444.3 +/- 127.7) mm Hg, P < 0.01]. EVLW had no relationship with PaO(2)/FiO(2), but DeltaEVLW after ARDS model induced had good correlation with DeltaPaO(2)/FiO(2) (r = -0.501, P < 0.001). When ARDS was induced, static lung compliance decreased from 26.9 +/- 8.4 to 16.4 +/- 5.0 (P < 0.01). (2) After mechanical ventilation with PEEP 2 h, EVLW in PEEP 10 cm H(2)O group and 15 cm H(2)O group were (14.7 +/- 4.5) ml/kg and (15.3 +/- 3.7) ml/kg respectively, which was significantly less than that before PEEP [(16.5 +/- 4.7) ml/kg and (18.4 +/- 6.0) ml/kg respectively, all P < 0.05]. But EVLW in 5 cm H(2)O group showed no difference during 2 h PEEP application. (3) After CO increase >/= 50% of the base value 1 h and 2 h, EVLW was (16.3 +/- 4.9) ml/kg and (16.9 +/- 6.9) ml/kg respectively, which did not differ from that of the baseline value [(15.1 +/- 4.6) ml/kg, all P > 0.05].

CONCLUSIONS

EVLW in ARDS sheep increased significantly and remained at the same level during the early phase of ARDS. PEEP had a markedly effect in reducing EVLW, while the increase of CO induced by dobutamine did not significantly raise EVLW.

摘要

目的

探讨早期急性呼吸窘迫综合征（ARDS）绵羊血管外肺水（EVLW）的变化以及呼气末正压（PEEP）和心输出量（CO）对EVLW的影响。

方法

静脉注射内毒素诱导绵羊ARDS模型，然后分为ARDS模型组（n = 12）、PEEP组（n = 21）和多巴酚丁胺组（n = 13）。PEEP组进一步分为三个亚组：PEEP 5 cm H₂O组（n = 7）、10 cm H₂O组（n = 8）和15 cm H₂O组（n = 6）。采用单指示剂热稀释技术测量EVLW。在诱导绵羊ARDS模型后6 h、分别给予PEEP（5、10、15 cm H₂O）机械通气2 h后以及CO增加≥基础值的50%（多巴酚丁胺静脉输注诱导）2 h后，观察EVLW、血流动力学和肺力学参数。

结果

（1）诱导绵羊ARDS时，EVLW从（12.8±4.7）ml/kg增加至（18.1±7.1）ml/kg（P < 0.01），ARDS早期（6 h）EVLW无显著变化（P > 0.05）。ARDS 0 h时PaO₂/FiO₂为（136.8±34.9）mmHg，高于内毒素注射前[（444.3±127.7）mmHg，P < 0.01]。EVLW与PaO₂/FiO₂无关，但ARDS模型诱导后的ΔEVLW与ΔPaO₂/FiO₂具有良好的相关性（r = -0.501，P < 0.001）。诱导ARDS时，静态肺顺应性从26.9±8.4降至16.4±5.0（P < 0.01）。（2）PEEP通气2 h后，PEEP 10 cm H₂O组和15 cm H₂O组的EVLW分别为（14.7±4.5）ml/kg和（15.3±3.7）ml/kg，显著低于PEEP前[分别为（16.5±4.7）ml/kg和（18.4±6.0）ml/kg，均P < 0.05]。但5 cm H₂O组在PEEP应用2 h期间EVLW无差异。（3）CO增加≥基础值的50% 1 h和2 h后，EVLW分别为（16.3±4.9）ml/kg和（16.9±6.9）ml/kg，与基线值[（15.1±4.6）ml/kg]无差异（均P > 0.05）。