Critical Care Department, Hospital del Mar, Passeig Marítim 25-29, 08003, Barcelona, Spain.
Research Group in Critical Disorders (GREPAC), Institut Hospital del Mar d'Investigacions Mèdiques (IMIM), Barcelona, Spain.
Intensive Care Med. 2019 Apr;45(4):488-500. doi: 10.1007/s00134-019-05566-5. Epub 2019 Feb 21.
Ventilator-induced diaphragm dysfunction or damage (VIDD) is highly prevalent in patients under mechanical ventilation (MV), but its analysis is limited by the difficulty of obtaining histological samples. In this study we compared diaphragm histological characteristics in Maastricht III (MSIII) and brain-dead (BD) organ donors and in control subjects undergoing thoracic surgery (CTL) after a period of either controlled or spontaneous MV (CMV or SMV).
In this prospective study, biopsies were obtained from diaphragm and quadriceps. Demographic variables, comorbidities, severity on admission, treatment, and ventilatory variables were evaluated. Immunohistochemical analysis (fiber size and type percentages) and quantification of abnormal fibers (a surrogate of muscle damage) were performed.
Muscle samples were obtained from 35 patients. MSIII (n = 16) had more hours on MV (either CMV or SMV) than BD (n = 14) and also spent more hours and a greater percentage of time with diaphragm stimuli (time in assisted and spontaneous modalities). Cross-sectional area (CSA) was significantly reduced in the diaphragm and quadriceps in both groups in comparison with CTL (n = 5). Quadriceps CSA was significantly decreased in MSIII compared to BD but there were no differences in the diaphragm CSA between the two groups. Those MSIII who spent 100 h or more without diaphragm stimuli presented reduced diaphragm CSA without changes in their quadriceps CSA. The proportion of internal nuclei in MSIII diaphragms tended to be higher than in BD diaphragms, and their proportion of lipofuscin deposits tended to be lower, though there were no differences in the quadriceps fiber evaluation.
This study provides the first evidence in humans regarding the effects of different modes of MV (controlled, assisted, and spontaneous) on diaphragm myofiber damage, and shows that diaphragm inactivity during mechanical ventilation is associated with the development of VIDD.
呼吸机诱导的膈肌功能障碍或损伤（VIDD）在接受机械通气（MV）的患者中非常普遍，但由于难以获得组织学样本，其分析受到限制。在这项研究中，我们比较了 Maastricht III （MSIII）和脑死亡（BD）器官捐献者以及接受胸部手术后接受控制或自主 MV （CMV 或 SMV）一段时间的对照组（CTL）的膈肌组织学特征。
在这项前瞻性研究中，从膈肌和股四头肌中获取活检。评估人口统计学变量、合并症、入院时的严重程度、治疗和通气变量。进行免疫组织化学分析（纤维大小和类型百分比）和异常纤维（肌肉损伤的替代物）的定量。
从 35 名患者中获得了肌肉样本。MSIII（n=16）比 BD（n=14）接受 MV 的时间更长（无论是 CMV 还是 SMV），并且还花费了更多的时间和更高的比例时间接受膈肌刺激（辅助和自主模式下的时间）。与 CTL（n=5）相比，两组膈肌和股四头肌的横截面积（CSA）均显著降低。MSIII 的股四头肌 CSA 明显低于 BD，但两组膈肌 CSA 无差异。那些接受 100 小时或更长时间无膈肌刺激的 MSIII 患者，其膈肌 CSA 减少，而其股四头肌 CSA 无变化。MSIII 膈肌中的内核比例趋于高于 BD 膈肌，而其脂褐素沉积的比例趋于较低，但股四头肌纤维评估无差异。
这项研究首次在人体中提供了关于不同 MV 模式（控制、辅助和自主）对膈肌肌纤维损伤影响的证据，并表明机械通气期间膈肌不活动与 VIDD 的发展有关。
