Respiratory Physiology Laboratory, Department of Neurology with Institute for Translational Neurology, University of Muenster, Muenster, Germany,
Respiratory Physiology Laboratory, Department of Neurology with Institute for Translational Neurology, University of Muenster, Muenster, Germany.
Respiration. 2019;98(4):301-311. doi: 10.1159/000501171. Epub 2019 Aug 6.
Twitch transdiaphragmatic pressure (twPdi) following magnetic stimulation (MS) of the phrenic nerves is the gold standard for non-volitional assessment of diaphragm strength. Expiratory muscle function can be investigated using MS of the abdominal muscles and measurement of twitch gastric pressure (twPgas).
To investigate whether twitch pressures following MS of the phrenic and lower thoracic nerve roots can be predicted noninvasively by diaphragm ultrasound parameters and volitional tests of respiratory muscle strength.
Sixty-three healthy subjects underwent standard spirometry, measurement of maximum inspiratory (PImax) and expiratory pressure (PEmax), and diaphragm ultrasound. TwPdi following cervical MS of the phrenic nerve roots and twPgas after lower thoracic MS (twPgas-Thor) were measured using esophageal and gastric balloon catheters inserted transnasally. Using surface electrodes, compound muscle action potentials (CMAP) were simultaneously recorded from the diaphragm or obliquus abdominis muscles, respectively.
Forced expiratory flow (FEF25-75) was significantly correlated with twPdi (r = 0.37; p = 0.003) and its components (twPgas and twitch esophageal pressure, twPes). Diaphragm excursion velocity during tidal breathing was correlated to twPes (r = 0.44; p = 0.02). No prediction of twitch pressures was possible from CMAP amplitude, forced vital capacity (FVC), or PImax. TwPgas-Thor was correlated with FEF25-75 (r = 0.46; p = 0.05) and diaphragm thickness at total lung capacity (r = 0.38; p = 0.04) but could not be predicted from CMAP amplitude, FVC, or PEmax.
TwPdi and twPgas-Thor cannot be predicted from volitional measures of respiratory muscle strength, diaphragm and abdominal CMAP, or diaphragm ultrasound. Invasive recording of esophageal and gastric pressures following MS remains indispensable for objective assessment of respiratory muscle strength.
经膈神经磁刺激（MS）后，膈膜跨膈压（twPdi）是评估膈膜强度的金标准。通过对腹肌进行 MS 刺激并测量 twitch 胃压（twPgas），可以研究呼气肌功能。
研究通过膈膜超声参数和呼吸肌力量的自主测试，能否无创预测膈神经和下胸神经根 MS 后的 twitch 压力。
63 名健康受试者接受了标准肺量测定、最大吸气（PImax）和呼气压力（PEmax）测量以及膈膜超声检查。通过经鼻插入食管和胃气囊导管，测量颈段 MS 膈神经根后 twPdi 和下段 MS（twPgas-Thor）后的 twPgas。使用表面电极，分别从膈膜或腹斜肌记录复合肌肉动作电位（CMAP）。
用力呼气流量（FEF25-75）与 twPdi（r = 0.37；p = 0.003）及其成分（twPgas 和 twitch 食管压，twPes）显著相关。潮气量呼吸时膈膜移动速度与 twPes 相关（r = 0.44；p = 0.02）。从 CMAP 幅度、用力肺活量（FVC）或 PImax 无法预测 twitch 压力。twPgas-Thor 与 FEF25-75 相关（r = 0.46；p = 0.05），与总肺容量时膈膜厚度相关（r = 0.38；p = 0.04），但不能从 CMAP 幅度、FVC 或 PEmax 预测。
不能从呼吸肌力量的自主测量、膈膜和腹 CMAP 或膈膜超声预测 twPdi 和 twPgas-Thor。MS 后食管和胃压的侵入性记录对呼吸肌力量的客观评估仍然不可或缺。
