Zhang Xianming, Wu Weiliang, Zhu Yongcheng, Jiang Ying, Du Juan, Chen Rongchang
Department of Respiratory Medicine, First Affiliated Hospital of Guizhou Medical University, Guizhou, China.
Respiratory Mechanics Lab, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
PLoS One. 2016 Jan 8;11(1):e0145694. doi: 10.1371/journal.pone.0145694. eCollection 2016.
It has proved that muscle paralysis was more protective for injured lung in severe acute respiratory distress syndrome (ARDS), but the precise mechanism is not clear. The purpose of this study was to test the hypothesis that abdominal muscle activity during mechanically ventilation increases lung injury in severe ARDS.
Eighteen male Beagles were studied under mechanical ventilation with anesthesia. Severe ARDS was induced by repetitive oleic acid infusion. After lung injury, Beagles were randomly assigned into spontaneous breathing group (BIPAPSB) and abdominal muscle paralysis group (BIPAPAP). All groups were ventilated with BIPAP model for 8h, and the high pressure titrated to reached a tidal volume of 6ml/kg, the low pressure was set at 10 cmH2O, with I:E ratio 1:1, and respiratory rate adjusted to a PaCO2 of 35-60 mmHg. Six Beagles without ventilator support comprised the control group. Respiratory variables, end-expiratory volume (EELV) and gas exchange were assessed during mechanical ventilation. The levels of Interleukin (IL)-6, IL-8 in lung tissue and plasma were measured by qRT-PCR and ELISA respectively. Lung injury scores were determined at end of the experiment.
For the comparable ventilator setting, as compared with BIPAPSB group, the BIPAPAP group presented higher EELV (427±47 vs. 366±38 ml) and oxygenation index (293±36 vs. 226±31 mmHg), lower levels of IL-6(216.6±48.0 vs. 297.5±71.2 pg/ml) and IL-8(246.8±78.2 vs. 357.5±69.3 pg/ml) in plasma, and lower express levels of IL-6 mRNA (15.0±3.8 vs. 21.2±3.7) and IL-8 mRNA (18.9±6.8 vs. 29.5±7.9) in lung tissues. In addition, less lung histopathology injury were revealed in the BIPAPAP group (22.5±2.0 vs. 25.2±2.1).
Abdominal muscle activity during mechanically ventilation is one of the injurious factors in severe ARDS, so abdominal muscle paralysis might be an effective strategy to minimize ventilator-induce lung injury.
已证实肌肉麻痹对重症急性呼吸窘迫综合征（ARDS）中受损肺脏具有更强的保护作用，但其确切机制尚不清楚。本研究的目的是验证以下假设：机械通气期间腹部肌肉活动会加重重症ARDS患者的肺损伤。
对18只雄性比格犬进行麻醉下的机械通气研究。通过反复输注油酸诱导重症ARDS。肺损伤后，比格犬被随机分为自主呼吸组（BIPAPSB）和腹部肌肉麻痹组（BIPAPAP）。所有组均采用双水平气道正压通气（BIPAP）模式通气8小时，高压滴定至潮气量达到6ml/kg，低压设定为10 cmH₂O，吸呼比为1:1，呼吸频率调整至动脉血二氧化碳分压（PaCO₂）为35 - 60 mmHg。6只未接受呼吸机支持的比格犬作为对照组。在机械通气期间评估呼吸变量、呼气末肺容积（EELV）和气体交换。分别采用实时荧光定量聚合酶链反应（qRT-PCR）和酶联免疫吸附测定（ELISA）法检测肺组织和血浆中白细胞介素（IL）-6、IL-8水平。在实验结束时确定肺损伤评分。
在可比的呼吸机设置下，与BIPAPSB组相比，BIPAPAP组的EELV更高（427±47 vs. 366±38 ml）、氧合指数更高（293±36 vs. 226±31 mmHg），血浆中IL-6（216.6±48.0 vs. 297.5±71.2 pg/ml）和IL-8（246.8±78.2 vs. 357.5±69.3 pg/ml）水平更低，肺组织中IL-6 mRNA（15.0±3.8 vs. 21.2±3.7）和IL-8 mRNA（18.9±6.8 vs. 29.5±7.9）表达水平更低。此外，BIPAPAP组的肺组织病理学损伤更少（22.5±2.0 vs. 25.2±2.1）。
机械通气期间腹部肌肉活动是重症ARDS的损伤因素之一，因此腹部肌肉麻痹可能是减轻呼吸机诱导性肺损伤的有效策略。
