Pressure support ventilation attenuates ventilator-induced protein modifications in the diaphragm
Pressure support ventilation attenuates ventilator-induced protein modifications in the diaphragm
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DOI：
10.1186/cc7010
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发表时间：
2008-01-01
期刊：
影响因子：
15.1
通讯作者：
Bazin, Jean-Etienne
中科院分区：
文献类型：
--
作者：
Futier, Emmanuel;Constantin, Jean-Michel;Bazin, Jean-Etienne
介绍控制性机械通气（CMV）引起膈肌蛋白质代谢的深刻变化，包括肌肉萎缩和严重的呼吸机引起的呼吸功能障碍。自主呼吸可以减少膈肌的变化。我们假设，在压力支持通气（PSV），保留膈肌活动，机械通气将限制mammatic蛋白catenos.Methods 42成年Sprague-Dawley大鼠被列入本前瞻性随机动物研究。腹膜内麻醉后，将动物随机分配至对照组或接受6或18小时的CMV或PSV。在处死和与C-14-苯丙氨酸孵育后，在隔膜的肋区域上测量体外蛋白质水解和蛋白质合成。结果与对照组相比，CMV感染18 h后，肌原纤维蛋白羰基化水平显著升高（33%，P = 0.0001），而CMV感染6 h后，肌原纤维蛋白羰基化水平无显著变化。CMV也使蛋白质合成在机械通气6小时后减少50%（P = 0.0012），在机械通气18小时后减少65%（P < 0.0001）。两种20 S蛋白酶体活性水平均被CMV增加。与CMV相比，PSV在6和18小时的蛋白水解没有明显增加。与对照组相比，PSV没有显著增加蛋白质合成。CMV和PSV均使机械通气18 h后的蛋白羰基水平分别从+63%（P < 0.001）和+82%（P < 0.0005）升高。PSV可能是限制呼吸机引起的呼吸功能障碍的一种有趣的替代方法。
Introduction Controlled mechanical ventilation (CMV) induces profound modifications of diaphragm protein metabolism, including muscle atrophy and severe ventilator-induced diaphragmatic dysfunction. Diaphragmatic modifications could be decreased by spontaneous breathing. We hypothesized that mechanical ventilation in pressure support ventilation (PSV), which preserves diaphragm muscle activity, would limit diaphragmatic protein catabolism.Methods Forty-two adult Sprague-Dawley rats were included in this prospective randomized animal study. After intraperitoneal anesthesia, animals were randomly assigned to the control group or to receive 6 or 18 hours of CMV or PSV. After sacrifice and incubation with C-14-phenylalanine, in vitro proteolysis and protein synthesis were measured on the costal region of the diaphragm. We also measured myofibrillar protein carbonyl levels and the activity of 20S proteasome and tripeptidylpeptidase II.Results Compared with control animals, diaphragmatic protein catabolism was significantly increased after 18 hours of CMV (33%, P = 0.0001) but not after 6 hours. CMV also decreased protein synthesis by 50% ( P = 0.0012) after 6 hours and by 65% (P < 0.0001) after 18 hours of mechanical ventilation. Both 20S proteasome activity levels were increased by CMV. Compared with CMV, 6 and 18 hours of PSV showed no significant increase in proteolysis. PSV did not significantly increase protein synthesis versus controls. Both CMV and PSV increased protein carbonyl levels after 18 hours of mechanical ventilation from +63% (P < 0.001) and +82% (P < 0.0005), respectively.Conclusions PSV is efficient at reducing mechanical ventilation-induced proteolysis and inhibition of protein synthesis without modifications in the level of oxidative injury compared with continuous mechanical ventilation. PSV could be an interesting alternative to limit ventilator-induced diaphragmatic dysfunction.