Qureshi Adnan I, Choundry Mohammad A, Mohammad Yousef, Chua Hoe C, Yahia Abutaher M, Ulatowski John A, Krendel David A, Leshner Robert T
Department of Neurology at The Johns Hopkins Hospital, Baltimore, MD, USA.
Med Sci Monit. 2004 Dec;10(12):CR684-9.
Although respiratory failure commonly occurs during the course of myasthenia gravis (MG), it is rarely described at presentation in patients with previously unrecognized MG.
MATERIAL/METHODS: We determined the prevalence and clinical characteristics of patients with respiratory failure associated with undiagnosed MG by review of the medical records of all patients who were diagnosed with MG related respiratory failure at four University hospitals. Respiratory failure was defined on the basis of a forced vital capacity < or =1 liter, negative inspiratory force < or =20 cm H2O, or requirement of mechanical ventilation.
Out of 51 MG patients with respiratory failure, 7(14%) patients had no previous diagnosis of MG. Another patient was identified after the review. The mean age of these 8 patients was 56 years (range 23-76 years); six were women. Five had previous episodes of unexplained respiratory failure. On initial evaluation, ocular or bulbar signs were present in 7 patients. The diagnosis of MG was made by edrophonium test (n=3), edrophonium test with positive acetylcholine antibody levels or repetitive nerve stimulation (n=2), repetitive nerve stimulation with positive acetylcholine antibody levels (n=2), and positive acetylcholine antibody levels alone (n=1). Seven patients required mechanical ventilation. Plasma exchange (n=7) or intravenous immunoglobulins (n=1) resulted in successful extubation or resolution of symptoms in all patients.
Respiratory failure can occur at presentation in MG. A high index of suspicion should be maintained in patients with previous history of unexplained respiratory failures.
虽然呼吸衰竭在重症肌无力（MG）病程中常见，但在既往未被识别的MG患者就诊时很少被描述。
材料/方法：我们通过回顾四家大学医院中所有被诊断为MG相关呼吸衰竭患者的病历，确定了与未确诊MG相关的呼吸衰竭患者的患病率和临床特征。呼吸衰竭的定义为用力肺活量≤1升、吸气负压≤20厘米水柱或需要机械通气。
在51例患有呼吸衰竭的MG患者中，7例（14%）之前未被诊断为MG。回顾后又发现1例患者。这8例患者的平均年龄为56岁（范围23 - 76岁）；6例为女性。5例曾有不明原因的呼吸衰竭发作。初次评估时，7例患者有眼部或延髓体征。通过依酚氯铵试验确诊MG的有3例，依酚氯铵试验联合乙酰胆碱抗体水平阳性或重复神经电刺激确诊的有2例，重复神经电刺激联合乙酰胆碱抗体水平阳性确诊的有2例，仅乙酰胆碱抗体水平阳性确诊的有1例。7例患者需要机械通气。血浆置换（7例）或静脉注射免疫球蛋白（1例）使所有患者成功拔管或症状缓解。
MG患者就诊时可发生呼吸衰竭。对于有不明原因呼吸衰竭病史的患者应保持高度怀疑。
