Department of Anaesthesiology and Intensive Care, Aarhus University Hospital, Aarhus, Denmark.
Department of Biomedicine, Aarhus University, Aarhus, Denmark.
Clin Neurophysiol. 2021 Jun;132(6):1347-1357. doi: 10.1016/j.clinph.2021.01.017. Epub 2021 Feb 20.
To investigate the sensitivity of muscle velocity recovery cycles (MVRCs) for detecting altered membrane properties in critically ill patients, and to compare this to conventional nerve conduction studies (NCS) and quantitative electromyography (qEMG).
Twenty-four patients with intensive care unit acquired weakness (ICUAW) and 34 healthy subjects were prospectively recruited. In addition to NCS (median, ulnar, peroneal, tibial and sural nerves) and qEMG (biceps brachii, vastus medialis and anterior tibial muscles), MVRCs with frequency ramp were recorded from anterior tibial muscle.
MVRC and frequency ramp parameters showed abnormal muscle fiber membrane properties with up to 100% sensitivity and specificity. qEMG showed myopathy in 15 patients (63%) while polyneuropathy was seen in 3 (13%). Decreased compound muscle action potential (CMAP) amplitude (up to 58%) and absent F-waves (up to 75%) were frequent, but long duration CMAPs were only seen in one patient with severe myopathy.
Altered muscle fiber membrane properties can be detected in patients with ICUAW not yet fulfilling diagnostic criteria for critical illness myopathy (CIM). MVRCs may therefore serve as a tool for early detection of evolving CIM.
CIM is often under-recognized by intensivists, and large-scale longitudinal studies are needed to determine its incidence and pathogenesis.
探讨肌肉速度恢复循环（MVRCs）检测危重病患者膜性质改变的敏感性，并与传统神经传导研究（NCS）和定量肌电图（qEMG）进行比较。
前瞻性招募 24 例重症监护病房获得性肌无力（ICUAW）患者和 34 名健康受试者。除了进行 NCS（正中神经、尺神经、腓总神经、胫神经和腓肠神经）和 qEMG（肱二头肌、股四头肌和胫骨前肌）外，还从胫骨前肌记录 MVRC 和频率斜坡。
MVRC 和频率斜坡参数显示肌肉纤维膜性质异常，具有高达 100%的敏感性和特异性。qEMG 显示 15 例患者（63%）存在肌病，3 例患者（13%）存在多发性神经病。复合肌肉动作电位（CMAP）幅度降低（高达 58%）和 F 波缺失（高达 75%）很常见，但仅在 1 例严重肌病患者中可见长时程 CMAP。
尚未达到危重病肌病（CIM）诊断标准的 ICUAW 患者可检测到肌肉纤维膜性质改变。因此，MVRC 可作为早期检测进展性 CIM 的工具。
CIM 常被重症监护医生忽视，需要进行大规模的纵向研究来确定其发病率和发病机制。
