Gorini M, Ginanni R, Spinelli A, Duranti R, Andreotti L, Scano G
Clinica Medica III, University of Florence, Italy.
Am Rev Respir Dis. 1990 Aug;142(2):289-94. doi: 10.1164/ajrccm/142.2.289.
In 15 patients with rheumatoid arthritis (RA) and in 12 age- and sex-matched normal subjects, we evaluated inspiratory muscle strength and respiratory control system. Inspiratory muscle strength was assessed by measuring maximal inspiratory pressure (MIP). Respiratory drive was assessed by evaluating surface electromyographic activity of the diaphragm (EMGd) during both room-air breathing and hypercapnic rebreathing. Compared to the predicted value (mean +/- 1.65 SD), MIP was significantly reduced in nine patients (60%). All told, we noticed a significant inverse relationship in the patients between MIP and duration of steroid therapy (p less than 0.01). During room-air breathing, both EMGd and mouth occlusion pressure (P0.1), expressed both in actual values and as percentage of MIP, were significantly greater in patients than in the normal control group (p less than 0.001 for both). Both EMGd and P0.1 (%MIP) response slopes to CO2 were significantly greater in patients than in the normal control group (p less than 0.01 and p less than 0.001, respectively) and significantly related to the functional stage of disease. During quiet breathing and for a PETCO2 of 60 mm Hg, both EMGd (p less than 0.01 and p less than 0.05, respectively) and P0.1 (%MIP) (p less than 0.01 and p = 0.001, respectively) were inversely related to MIP. These results indicate that RA patients may exhibit inspiratory muscle weakness and increased respiratory drive. Steroid myopathy and rheumatoid myositis could explain the reduction in MIP, whereas neural afferents arising from respiratory muscle, lung, or joint receptors could be involved in the observed increase in neural drive.
在15例类风湿性关节炎（RA）患者以及12名年龄和性别匹配的正常受试者中，我们评估了吸气肌力量和呼吸控制系统。通过测量最大吸气压（MIP）来评估吸气肌力量。通过评估静息呼吸和高碳酸血症再呼吸期间膈肌的表面肌电图活动（EMGd）来评估呼吸驱动力。与预测值（平均值±1.65标准差）相比，9例患者（60%）的MIP显著降低。总体而言，我们注意到患者的MIP与类固醇治疗持续时间之间存在显著的负相关（p<0.01）。在静息呼吸期间，患者的EMGd和口腔阻断压（P0.1），无论是实际值还是占MIP的百分比，均显著高于正常对照组（两者p<0.001）。患者的EMGd和P0.1（%MIP）对CO2的反应斜率均显著大于正常对照组（分别为p<0.01和p<0.001），且与疾病功能阶段显著相关。在安静呼吸和呼气末二氧化碳分压（PETCO2）为60 mmHg时，EMGd（分别为p<0.01和p<0.05）和P0.1（%MIP）（分别为p<0.01和p = 0.001）均与MIP呈负相关。这些结果表明，RA患者可能表现出吸气肌无力和呼吸驱动力增加。类固醇肌病和类风湿性肌炎可以解释MIP的降低，而呼吸肌、肺或关节感受器产生的神经传入可能参与了观察到的神经驱动增加。
