Hillman D R, Finucane K E
Department of Pulmonary Physiology, Sir Charles Gairdner Hospital, Nedlands, Australia.
Am Rev Respir Dis. 1988 Jun;137(6):1401-5. doi: 10.1164/ajrccm/137.6.1401.
To compensate for diaphragmatic weakness, intercostal/accessory muscles may be recruited in inspiration and/or abdominal muscles in expiration with relaxation during subsequent inspiration. As a consequence, for a given decrease in pleural pressure (Ppl) during quiet inspiration (qi), abdominal pressure (Pab) should either undergo a smaller increase than normal or, in severe cases, decrease. If so, the ratio of change in Pab to Ppl during qi (delta Pab/delta Ppl(qi], which is normally less than -1 when upright, should increase, approaching +1 in profound diaphragmatic weakness. To examine the relationship between degree of diaphragmatic weakness and delta Pab/delta Ppl(qi), we measured (erect and supine) anteroposterior rib cage and abdominal motion, Pab, Ppl, and transdiaphragmatic pressure (Pdi) during qi, maximal inspiration (Pdi(max)mi) and maximal inspiratory effort at FRC (Pdi(max)FRC) in 10 patients with bilateral and 8 with unilateral diaphragmatic weakness. Pdi(max)mi and Pdi(max)FRC were low in all patients. delta Pab/delta Ppl(qi) (erect) was increased in all patients (0.28 +/- 0.7; mean +/- SD) and correlated closely with both Pdi(max)mi (r = -0.89, p less than 0.001) and Pdi(max)FRC (r = -0.76, p less than 0.001). There was extensive overlap in the data between unilateral and bilateral diaphragmatic weakness. The ratio of delta Pdi during qi to Pdi(max)FRC was less than 0.31 in all patients. The results suggest that delta Pab/delta Ppl(qi) is a useful index of the degree of diaphragmatic weakness and that the functional consequences of unilateral and bilateral weakness are not rigidly separable.(ABSTRACT TRUNCATED AT 250 WORDS)
为了代偿膈肌无力，吸气时肋间肌/辅助肌可能会被募集，呼气时腹肌可能会被募集，随后吸气时则放松。因此，在安静吸气（qi）过程中，若胸膜腔内压（Ppl）有一定程度的下降，腹内压（Pab）的升高幅度应小于正常情况，或在严重病例中腹内压下降。如果是这样，qi期间Pab变化与Ppl变化的比值（delta Pab/delta Ppl(qi]，直立时该值正常情况下小于-1）应增大，在严重膈肌无力时接近+1。为了研究膈肌无力程度与delta Pab/delta Ppl(qi)之间的关系，我们测量了10例双侧膈肌无力患者和8例单侧膈肌无力患者在直立位和仰卧位时的胸廓前后径及腹部运动、Pab、Ppl和跨膈压（Pdi），测量时间点包括qi、最大吸气时（Pdi(max)mi）以及功能残气量（FRC）时的最大吸气努力（Pdi(max)FRC）。所有患者的Pdi(max)mi和Pdi(max)FRC均较低。所有患者直立位时的delta Pab/delta Ppl(qi)均升高（0.28±0.7；平均值±标准差），且与Pdi(max)mi（r = -0.89，p＜0.001）和Pdi(max)FRC（r = -0.76，p＜0.001）密切相关。单侧和双侧膈肌无力的数据有广泛重叠。所有患者qi期间delta Pdi与Pdi(max)FRC的比值均小于0.31。结果表明，delta Pab/delta Ppl(qi)是膈肌无力程度的一个有用指标，且单侧和双侧无力的功能后果并非严格可区分的。（摘要截选至250词）
