Kreitzer S M, Feldman N T, Saunders N A, Ingram R H
Am J Med. 1978 Jul;65(1):89-95. doi: 10.1016/0002-9343(78)90697-6.
Bilateral diaphragmatic paralysis was suspected in a patient presenting with hypercapnic respiratory failure who exhibited paradoxic (i.e., inward) abdominal movement on inspiration during tidal breathing in the supine posture; no paradoxic abdominal motion was observed at the bedside with the patient upright. Transdiaphragmatic pressure measurements established the diagnosis of diaphragmatic paralysis, although 20 cm H2O pressure developed across the diaphragm during the latter part of a forced expiration, presumably due to the development of passive tension in the diaphragm as it was stretched near residual volume. Analysis of the relative motion of the rib cage and abdomen during breathing by the use of magnetometers confirmed the presence of abdominal paradox throughout the breathing cycle when the patient was supine, and established that paradoxic motion of the abdomen also occurred when the patient was in the erect posture but only in the latter half of inspiration. Our findings confirm that the use of transdiaphragmatic pressure measurements and magnetometry will help to quantify diaphragmatic function, that passive tension develops in the paralyzed diaphragm near residual volume and should not be confused with active contraction, and that paradoxic motion of the abdomen may be masked from the clinician when the patient is erect.
一名出现高碳酸血症性呼吸衰竭的患者被怀疑双侧膈肌麻痹，该患者在仰卧位潮气呼吸时吸气期出现反常（即向内）腹部运动；患者直立位时床边未观察到反常腹部运动。经膈压测量确诊为膈肌麻痹，尽管在用力呼气后期膈肌上产生了20 cmH₂O的压力，这可能是由于膈肌在接近残气量时被拉伸而产生了被动张力。使用磁力计分析呼吸过程中胸廓和腹部的相对运动，证实患者仰卧位时在整个呼吸周期中均存在腹部反常运动，并确定患者直立位时腹部反常运动也会出现，但仅在吸气后半期出现。我们的研究结果证实，经膈压测量和磁力测定有助于量化膈肌功能，麻痹的膈肌在接近残气量时会产生被动张力，不应与主动收缩相混淆，并且当患者直立时，临床医生可能会忽略腹部的反常运动。
