Zhao Xiao-wei, Zhang Jian-peng, Huang Xian, Liu You-ning
Department of Respiratory Diseases, General Hospital of Armed Police Forces, Beijing 100039, China.
Zhonghua Yi Xue Za Zhi. 2009 Dec 15;89(46):3266-70.
To investigate the effects of positive end-expiratory pressure (PEEP) ventilation upon respiratory function and lung surfactant protein B (SP-B)/SP-C in seawater respiratory distress syndrome (SW-RDS) rabbit.
Twenty-four female New Zealand rabbits were randomly equally divided into three groups:conventional mechanical ventilation (CMV) group, PEEP group, and control group. After anesthesia and tracheal intubation followed by 20 minutes of CMV, SW-RDS model was established by lung perfusion of artificial seawater through tracheal intubation. Then the CMV group ventilated for 6 hours (each parameter unchanged); PEEP group ventilated with PEEP of 8 cm H2O for 2 hours based on prior parameters and subsequently with CMV for 4 hours; control group without ventilation after modeling. Oxygenation indices and lung compliance were continuously monitored during ventilation. After ventilation, the rabbits in study groups were sacrificed while those dying a natural death in the control group selected. Bronchoalveolar lavage fluid of the left lung was collected to determine the alveolar surface tension and the right lung was harvested to measure the mRNA expression of SP-B/SP-C by real-time PCR as well as SP-B protein by Western blotting.
After modeling, the data of lung compliance and oxygenation indices became significantly worse in every group but without statistical difference in three groups. All rabbits in control group died within 15 minutes of ventilator withdrawal. After receiving PEEP ventilation for 30 minutes, these indices significantly improved compared with CMV group in which there was no significant change of the indices (P < 0.05). Minimal alveolar surface tension in CMV group (mN/m, 30.8 +/- 6.3) was greater than in PEEP group (21.1 +/- 4.4, P < 0.05) and control group (23.6 +/- 4.6, P < 0.05); SP-B/SP-C mRNA relative expression (0.37 +/- 0.15/0.60 +/- 0.19) and SP-B relative protein abundance (0.38 +/- 0.17) in CMV group were obviously lower than in PEEP group (0.73 +/- 0.15/0.92 +/- 0.40, 0.52 +/- 0.22, P < 0.05).
PEEP ventilation can improve the oxygenation indices and lung compliance in SW-RDS animals. And such an effect is correlated with both the mRNA expressions of SP-B/SP-C and mechanical distension.
探讨呼气末正压（PEEP）通气对海水吸入性呼吸窘迫综合征（SW-RDS）兔呼吸功能及肺表面活性蛋白B（SP-B）/SP-C的影响。
将24只雌性新西兰兔随机均分为三组：传统机械通气（CMV）组、PEEP组和对照组。麻醉并气管插管后进行20分钟CMV，然后经气管插管向肺内灌注人工海水建立SW-RDS模型。之后，CMV组通气6小时（各参数不变）；PEEP组先按原参数通气2小时，PEEP为8 cm H₂O，随后CMV通气4小时；对照组建模后不进行通气。通气过程中持续监测氧合指数和肺顺应性。通气结束后，处死研究组家兔，选取对照组自然死亡的家兔。收集左肺支气管肺泡灌洗液测定肺泡表面张力，取右肺通过实时PCR检测SP-B/SP-C的mRNA表达，并用蛋白质印迹法检测SP-B蛋白。
建模后，各组肺顺应性和氧合指数数据均明显变差，但三组间无统计学差异。对照组所有家兔在撤机后15分钟内死亡。PEEP通气30分钟后，与CMV组相比，这些指标显著改善，而CMV组指标无明显变化（P<0.05）。CMV组最小肺泡表面张力（mN/m，30.8±6.3）大于PEEP组（21.1±4.4，P<0.05）和对照组（23.6±4.6，P<0.05）；CMV组SP-B/SP-C mRNA相对表达量（0.37±0.15/0.60±0.19）和SP-B相对蛋白丰度（0.38±0.17）明显低于PEEP组（0.73±0.15/0.92±0.40，0.52±0.22，P<0.05）。
PEEP通气可改善SW-RDS动物的氧合指数和肺顺应性。这种作用与SP-B/SP-C的mRNA表达及机械扩张均有关。
