重症肌无力患者肺功能改变及其与临床肌无力严重度的相关分析

目的 检测重症肌无力(MG)患者的肺功能改变,探讨其呼吸肌力变化与临床肌无力严重度、肺功能改变的关系. 方法 选取解放军第309医院MG治疗中心自2008年8月至2009年5月收治的Ⅰ型MG患者16例,Ⅱ型50例,选取同期健康体检者30例做为对照,检测并比较呼吸肌力最大吸气压(PIM)、最大呼气压(PEM)、0.1s口腔闭合压(P0.1)]、和肺功能肺活量(VC)、最大自主通气量(MVV)、峰流速(PF)、总气道阻力(R5)、中心气道阻力(R20]改变,并对Ⅱ型MG患者的呼吸肌力变化与临床肌无力严重度、MG患者呼吸肌力与肺功能的改变行相关性分析. 结果 与对照组比较,Ⅰ型MG患者MVV、PM降低,R20、R5增高,Ⅱ型MG患者VC、MVV、PF、PIM、PEM降低,R5增高,差异有统计学意义(P<0.05).与Ⅰ型MG患者比较,Ⅱ型MG患者PIM、PEM蹦减少,R5、R20增高,差异有统计学意义(P<0.05);Ⅱ型MG患者的PIM、PEM、MVV、VC与肌无力严重度绝对分数均呈正相关关系(r=0.550,P=0.002;r=0.653,P=0.000;r=0.511,P=0.000;r=0.353,P=0.010);MG患者的PIM、PEM分别与VC、MVV、PF均呈正相关关系(P<0.05),且PEM与PIM之间也呈正相关关系(r=0.650,P=0.000). 结论 Ⅰ型MG患者在疾病早期无明显呼吸肌无力表现时可有呼吸肌力减退和呼吸肌耐受力降低,故MVV、PIM、R20、R5可作为早期诊断MG的敏感指标;Ⅱ型MG患者呼吸阻力的增高和呼吸肌力的受损比Ⅰ型MG更严重.且这种损害伴有肌无力严重度绝对分数的增高;呼吸肌力的减退与肺功能的减退呈一致性.

Changes of pulmonary function and its relation with severity of myasthenia in patients with myasthenia gravis

Objective To explore the relation between the changes of respiratory muscle strength and both the changes of pulmonary function and the severity of myasthenia in patients with myasthenia gravis (MG). Methods We measured the respiratory muscle strength (maximal inspiratory pressure PIM], maximal expiratory pressure PEM] and P0.1) and pulmonary function (vital capacity VC],maximal voluntary ventilation MVV], peak flow PF], R5 and R20) of 50 patients with type Ⅱ MG (group B), 16 patients with type Ⅰ MG (group A) and 30 healthy controls (group C). In addition, we analyzed the correlation between the pulmonary function and both the changes of respiratory muscle strength and the severity of myasthenia in group B. Results Comparison with group C, patients in group A had significantly decreased level of MW and P PIM, and statistically increased level of R20 and R5 (P<0.05);additionally, the level of VC, MW, PF, PIM and PEM, in group B decreased markedly with R20 increased markedly only as compared with that in the controls (P<0.05). Patients in group B showed significantly decreased level of PIm and PEM, and increased level of R20 and R5 as compared with the patients in group A (P<0.05). The level of PIM< PEM. MW and VC in group B was positively correlated to the absolute scores of severity of myasthenia in patients with type II MG (r=0.550, P=0.002; r=0.653, P=0.000; r=0.511,P=0.000; r=0.353, P=0.010). The level of PIM had positive correlation with the level of MW, VCand PF, so was the level of PEM. Positive correlation was also found between the level of PIM and PEM.Conclusions PatientswithtypeIMGinthe early stagemaynotmanifested ashavingmyasthenia,buthad weak strength and tolerance of respiratory muscle, thus, the level of MW, PIM,R10 and R5 might be the sensitive indexes in its early diagnosis. Changes of pulmonary function and respiratory muscle strength in patients with type Ⅱ MG were more obvious as compared with those in patients with type Ⅱ MG and these changes were positively correlated to the absolute scores of severity of myasthenia, which were consistent with the respiratory muscle strength and ventilatory function defects.