Intermittent spontaneous breathing protects the rat diaphragm from mechanical ventilation effects
Intermittent spontaneous breathing protects the rat diaphragm from mechanical ventilation effects
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DOI：
10.1097/01.ccm.0000191250.32988.a3
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发表时间：
2005-12-01
影响因子：
8.8
通讯作者：
Decramer, M
中科院分区：
文献类型：
--
作者：
Gayan-Ramirez, G;Testelmans, D;Decramer, M
目的：短期机械通气已被证明可以减少膈肌张力和纤维尺寸。我们假设在机械通气过程中间歇性自主呼吸将最大限度地减少机械通气对膈肌力量和转录因子（MyoD和肌生成素）表达水平的影响。设计：随机对照实验。动物基础科学实验室，实验对象：雄性Wistar大鼠，体重350-500克。干预措施：麻醉和气管切开的大鼠进行24小时的自主呼吸（SB，n = 5），持续受控机械通气24小时（CMV，n = 7）或受控机械通气伴间歇性自主呼吸：每5小时60分钟机械通气，重复4次（ISB 60，n = 8）或每5小时55分钟机械通气，重复4次（SB 5，n = 9）。将它们与不受干预的对照动物进行比较（C，n = 5）.测量结果和主要结果：正常对照组和SB组的膈肌力-频率曲线形态与ISB组和CMV组有显著性差异;特别是，与对照组和SB相比，ISB和CMV的平均渐近力更小。CMV导致1型膈肌的显著降低（-26%，p < .05 vs. C）和IIx/B型（-39%，p < .005 vs. C和SB）横截面积，而这在IS B组中未观察到。膈肌MyoD蛋白表达在ISB 60后显著降低（-35%，p < .0001 vs. C和SB），在CMV后甚至更多（-73%，p < .0001 vs.其他）。在肌细胞生成素蛋白水平上观察到相同的模式。膈肌MyoD和肌细胞生成素蛋白水平和膈肌forces.Conclusions之间的正相关关系：数据表明，间歇性自主呼吸过程中的机械通气可能会尽量减少控制机械通气对膈肌的力量，纤维尺寸和转录因子的表达的有害影响。
Objective: Short-term mechanical ventilation has been proven to reduce diaphragm force and fiber dimensions. We hypothesized that intermittent spontaneous breathing during the course of mechanical ventilation would minimize the effects of mechanical ventilation on diaphragm force and expression levels of transcription factors (MyoD and myogenin).Design: Randomized, controlled experiment.Setting. Animal basic science laboratory.Subjects: Male Wistar rats, weighing 350-500 g.Interventions: Anesthetized and tracheotomized rats were submitted to either 24 hrs of spontaneous breathing (SB, n = 5), 24 hrs of continuous controlled mechanical ventilation (CMV, n = 7), or controlled mechanical ventilation with intermittent spontaneous breathing: 60 mins every 5 hrs of mechanical ventilation repeated four times (ISB60, n = 8) or 5 mins every 5 hrs 55 mins of mechanical ventilation repeated four times (SB5, n = 9). They were compared with control animals free from intervention (C, n = 5).Measurements and Main Results: The profile of the diaphragm force-frequency curve of the controls and SB group was significantly different from that of the ISB and CMV groups; especially, the mean asymptotic force was less in the ISB and CMV compared with controls and SB. CMV resulted in a significant decrease in the diaphragm type 1 (-26%, p < .05 vs. C) and type IIx/b (-39%, p < .005 vs. C and SB) cross-sectional area, whereas this was not observed in the ISB groups. Diaphragm MyoD protein expression was significantly decreased after ISB60 (-35%, p < .0001 vs. C and SB) and even more after CMV (-73%, p < .0001 vs. others). The same pattern was observed with myogenin protein levels. Positive relationships between diaphragm MyoD and myogenin protein levels and diaphragm force were observed.Conclusions: The data demonstrated that intermittent spontaneous breathing during the course of mechanical ventilation may minimize the deleterious effect of controlled mechanical ventilation on diaphragm force, fiber dimensions, and expression of transcription factors.