Braun N M, Arora N S, Rochester D F
Thorax. 1983 Aug;38(8):616-23. doi: 10.1136/thx.38.8.616.
We studied 53 patients with proximal myopathy to determine at what level of muscle weakness hypercapnic respiratory failure is likely, and which tests of pulmonary function or respiratory muscle strength would best suggest this development. Respiratory muscle strength was determined from maximal static efforts and in half the patients, both inspiratory and expiratory muscle strengths were less than 50% of normal. In the 37 patients without lung disease respiratory muscle weakness was accompanied by significant decreases in vital capacity, total lung capacity, and maximum voluntary ventilation; by significant increases in residual volume and arterial carbon dioxide tension (PaCO2); and greater likelihood of dependence on ventilators, atelectasis, and pneumonia. Hypercapnia was particularly likely when respiratory muscle strength was less than 30% of normal in uncomplicated myopathy, and when vital capacity was less than 55% of the predicted value in any patient.
我们研究了53例近端肌病患者，以确定在何种肌无力水平时可能发生高碳酸血症性呼吸衰竭，以及哪些肺功能或呼吸肌力量测试能最好地提示这种进展。通过最大静态用力来测定呼吸肌力量，半数患者的吸气和呼气肌力量均低于正常的50%。在37例无肺部疾病的患者中，呼吸肌无力伴有肺活量、肺总量和最大自主通气量显著降低；残气量和动脉血二氧化碳分压（PaCO2）显著升高；以及更有可能依赖呼吸机、发生肺不张和肺炎。在无并发症的肌病中，当呼吸肌力量低于正常的30%时，以及在任何患者中肺活量低于预测值的55%时，高碳酸血症尤其可能发生。
