Mier-Jedrzejowicz A, Brophy C, Moxham J, Green M
Department of Respiratory Muscle, Physiology, Brompton Hospital, London, England.
Am Rev Respir Dis. 1988 Apr;137(4):877-83. doi: 10.1164/ajrccm/137.4.877.
Thirty patients with breathlessness and diaphragm weakness were studied by measuring transdiaphragmatic pressures during maximal inspirations to total lung capacity, maximal static inspiratory efforts from residual volume, and maximal sniffs from functional residual capacity. Maximal static respiratory mouth pressures were also recorded, and rib cage and abdominal movements were monitored with pairs of magnetometers. Sniff transdiaphragmatic pressure was abnormally low in all patients and was correlated with transdiaphragmatic pressure during other maneuvers, and with maximal static inspiratory mouth pressures. There was no relationship between the severity of dyspnea and transdiaphragmatic pressure in the group as a whole. The weakest patients had orthopnea and paradoxical inward inspiratory motion of the anterior abdominal wall; measurements suggested that at least 30 cm H2O transdiaphragmatic pressure was required to overcome the hydrostatic pressure of the abdominal contents. By contrast, patients with mild diaphragm weakness had neither orthopnea nor abdominal paradox. Thus, patients with breathlessness and diaphragm dysfunction may have varying degrees of diaphragm weakness that may be difficult to detect clinically; the diagnosis and quantification of diaphragm weakness requires the measurement of transdiaphragmatic pressure.
对30例伴有气促和膈肌无力的患者进行了研究，通过在最大吸气至肺总量、从残气量进行最大静态吸气努力以及从功能残气量进行最大嗅气动作时测量跨膈压。还记录了最大静态呼吸口压，并用成对的磁力计监测胸廓和腹部运动。所有患者的嗅气跨膈压均异常低，且与其他动作时的跨膈压以及最大静态吸气口压相关。在整个研究组中，呼吸困难的严重程度与跨膈压之间没有关系。最虚弱的患者有端坐呼吸和前腹壁吸气时反常的向内运动；测量结果表明，至少需要30 cmH₂O的跨膈压来克服腹腔内容物的静水压力。相比之下，轻度膈肌无力的患者既没有端坐呼吸也没有腹部反常运动。因此，伴有气促和膈肌功能障碍的患者可能有不同程度的膈肌无力，临床上可能难以检测到；膈肌无力的诊断和量化需要测量跨膈压。
