Zielonka T, Kostera-Pruszczyk A, Ryniewicz B, Korczyński P, Szyluk B
Department of Respiratory Medicine, Warsaw Medical University, Warsaw, Poland.
J Physiol Pharmacol. 2006 Sep;57 Suppl 4:409-16.
Myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction. Clinical symptoms are caused by weakness and increased fatigability of various muscle groups. Myasthenia may lead to significant respiratory dysfunction. The aim of our study was to estimate lung function in children with MG. We tested 23 non-smoking patients (18 girls and 5 boys) aged 7-18 years. Whole-body plethysmography and spirometry were performed in all patients. In 33% of the patients a decrease in VC <80% of predicted value was observed (VC = 89 +/-19%), but the analysis of TLC revealed restrictive pattern only in one patient (TLC = 102 +/-17%). In more than 75% of the children the value of RV above 120% of predicted value was found (RV = 146 +/-54%). Spirometric obstructive pattern measured by FEV1%VC <70% was not observed, although in 56% of the patients airway resistance was increased (Raw = 132 +/-44%). In 45% of the patients a decrease of PEF (76 +/-14%) was observed. In MG children true restrictive pulmonary impairment is rarely observed and a decrease in VC in these patents seems to result mainly from functional restriction provoked by an increase in RV. Spirometry is not an optimum method to assess functional changes in MG patients. The assessment of additional measures such as TLC, RV, and Raw is desirable.
重症肌无力（MG）是一种神经肌肉接头处的自身免疫性疾病。临床症状由各种肌群的无力和易疲劳性增加引起。重症肌无力可能导致严重的呼吸功能障碍。我们研究的目的是评估重症肌无力患儿的肺功能。我们测试了23名7至18岁的非吸烟患者（18名女孩和5名男孩）。对所有患者进行了全身体积描记法和肺活量测定法。在33%的患者中观察到肺活量（VC）下降至预测值的<80%（VC = 89±19%），但肺总量（TLC）分析仅在一名患者中显示为限制性模式（TLC = 102±17%）。在超过75%的儿童中发现残气量（RV）值高于预测值的120%（RV = 146±54%）。虽然在56%的患者中气道阻力增加（气道阻力Raw = 132±44%），但未观察到用力呼气量占肺活量百分比（FEV1%VC）<70%所测得的肺量计阻塞性模式。在45%的患者中观察到呼气峰值流速（PEF）下降（76±14%）。在重症肌无力儿童中很少观察到真正的限制性肺损害，这些患者的肺活量下降似乎主要是由残气量增加引起的功能受限所致。肺活量测定法不是评估重症肌无力患者功能变化的最佳方法。评估诸如肺总量、残气量和气道阻力等其他指标是可取的。
