Respiratory muscle training in patients with moderate to severe myasthenia gravis.

BACKGROUND: Myasthenia gravis (MG) is a specific autoimmune disease characterized by weakness and fatigue. MG may affect also the respiratory muscles causing symptoms that may vary from dyspnea on severe exertion to dyspnea at rest. This study was undertaken in order to determine the effects of respiratory muscle training on respiratory muscle performance, spirometry data and the grade of dyspnea in patients with moderate to severe generalized MG. METHODS: Eighteen patients with MG were studied and divided into 2 groups: Group A included 10 patients (3 males and 7 females aged 29-68) with moderate MG, and Group B that included 8 patients (5 males and 3 females aged 21-74) with severe MG. Patients in Group A received both inspiratory and expiratory muscle training for 1/2 h/day, 6 times a week, for 3 months, while patients in Group B followed the same protocol but had inspiratory muscle training only. RESULTS: Mean PImax increased significantly from 56.6 +/- 3.9 to 87.0 +/- 5.8 cm H2O (p < 0.001) in Group A, and from 28.9 +/- 5.9 to 45.5 +/- 6.7 cm H2O (p < 0.005) in Group B. The mean PEmax also increased significantly in patients in Group A, but remained unchanged in the patients in Group B. The respiratory muscle endurance also increased significantly, from 47.9 +/- 4.0 to 72.0 +/- 4.2%, p < 0.001, in patients of Group A, and from 26.0 +/- 2.9 to 43.4 +/- 3.8, p < 0.001, in patients in Group B. The improved respiratory muscle performance was associated with a significant increase in the FEV1 values, and in the FVC values, in patients of both groups. Mean dyspnea index score also increased significantly from 2.6 +/- 0.8 to 3.6 +/- 0.4 (p < 0.005) in Group A, and from 0.7 +/- 0.2 to 2.0 +/- 0.2 (p < 0.001) in Group B. CONCLUSIONS: Specific inspiratory threshold loading training alone, or combined with specific expiratory training, markedly improved respiratory muscle strength and endurance in patients with MG. This improvement in respiratory muscle performance was associated with improved lung function and decreased dyspnea. Respiratory muscle training may prove useful as a complementary therapy with the aim of reducing dyspnea symptoms, delay the breathing crisis and the need for mechanical ventilation in patients with MG.

[Specific inspiratory muscle training in chronic hemodialysis].

Chronic renal failure can result in a variety of conditions leading to muscle weakness. We investigated inspiratory muscle (IM) performance and functional capacity in chronic renal failure before and after specific inspiratory muscle training (SIMT). 9 men and 1 woman, ranging in age from 22-78 years, while on chronic hemodialysis received SIMT 3 times a week, for 3 months, while 10 others received sham training. Static inspiratory pressures, IM endurance and functional capacity were reduced in most subjects. Following SIMT, IM performance improved significantly and was associated with improved functional capacity, but not in the control group. We conclude that patients with chronic renal failure undergoing maintenance hemodialysis have reduced IM performance, and SIMT improves functional capacity.

[Post-transfusion purpura].

Post-transfusion purpura (PTP) is a rare syndrome that may develop a week after blood transfusion. In this syndrome, which occurs mainly in women, blood transfusion is followed by severe thrombocytopenia a week later. A 72-year-old woman with this syndrome is presented. High-dose intravenous gamma-globulin resulted in prompt resolution of her thrombocytopenia. The basic pathophysiologic mechanism of PTP is the development of an alloantibody to a human platelet antigen. The mystery of PTP is why the patients' own, as well as transfused PLA1-negative platelets, are destroyed.

[Effect of corticosteroids on inspiratory muscle function].

Functional alteration in inspiratory muscles was evaluated in patients receiving corticosteroids for nonrespiratory diseases. Inspiratory muscle strength, as expressed by maximal inspiratory mouth pressure (PImax), and inspiratory muscle endurance (PmPeak/PImax), determined with a pressure threshold breathing device, were evaluated in 8 patients with normal pulmonary and inspiratory muscle function. There was a gradual decrease in both inspiratory muscle strength and endurance when corticosteroids were given. Tapered decrease in steroid dosage resulted in marked improvement in both strength and endurance, and the improvement was even more significant 6 months later. We also evaluated the ability of specific inspiratory muscle training to prevent the effects of therapeutic corticosteroids on inspiratory muscle function in 6 patients, as compared to 6 control patients who received sham training. Following corticosteroids there was a gradual decrease in both inspiratory muscle strength and endurance in those getting sham training. However, there was no significant change in inspiratory muscle function in those getting inspiratory muscle training. We conclude that corticosteroids result in significant deterioration in respiratory muscle function. This weakness is reversible by tapering steroid dosage, but can be prevented by specific inspiratory muscle training during corticosteroid treatment.

[AIDS-related dementia].

Dementia is a common process in which there is gradual decrease in mental function due to disease of either cortical or subcortical structures. The numerous causes of dementia can be divided into those in which dementia is the primary manifestation, as in Alzheimer's disease, or secondary to chronic disease, neoplasms, endocrine and metabolic disorders and chronic infections. The dementia in AIDS is usually part of the syndrome of acquired immunodeficiency and may be its first manifestation.

Clinical course of recent-onset atrial fibrillation treated with oral propafenone.

Atrial fibrillation (AF) is one of the most common cardiac arrhythmias in the adult population. Propafenone is a class 1c antiarrhythmic agent that has an electrophysiologic profile suggesting that it might be potentially effective in recent-onset AF. The present study was undertaken, therefore, to examine the time course as well as the frequency of successful conversion in patients with recent-onset AF treated with propafenone administered orally. Fifty patients with recent-onset AF were recruited into 2 groups: 25 patients were given propafenone, 150 mg every 4 h, and 25 patients served as a control group and received verapamil (a drug known to slow the ventricular response but not to restore sinus rhythm) 40 mg, every 4 h and up to 48 h or until conversion to sinus rhythm occurred. Of the 50 patients, 2 refused to continue the study and another 2 were excluded because of left heart failure. Conversion to sinus rhythm occurred in 21 of 24 patients (87 percent) in the propafenone group as compared with 9 of 22 (41 percent) in the verapamil group (p < 0.001). In 10 patients in the propafenone group, conversion occurred within 12 h, within 24 h in another 9 patients, and between 24 and 48 h in the remaining 2 patients. There was no correlation between the duration of AF prior to entry into the study and the subsequent incidence of and time to conversion with propafenone. With respect to cause of AF, all groups showed a high incidence of conversion. Two patients developed heart failure during treatment and one patient (in the verapamil group) developed embolic stroke while still having atrial fibrillation. We conclude that in patients with AF, the prognosis for conversion to sinus rhythm within 48 h, with propafenone, is excellent (87 percent) and safe.

[Unusual treatment for myasthenia gravis associated with asthma].

Abnormal antibody production is now recognized as the basis of many diseases, among them myasthenia gravis (MG) and a variant of bronchial asthma. It is not unusual to find 2 or even more of these diseases in the same patient. A patient in whom both MG and bronchial asthma were diagnosed is presented. In both diseases the respiratory muscles are mechanically disadvantaged, which may result in severe dyspnea. In our case, despite specific treatment for both diseases severe attacks of dyspnea still occurred. Specific inspiratory muscle training was followed by significant clinical improvement. There was indirect evidence that respiratory muscles can be trained in patients with MG. Thus, patients with MG with respiratory muscle involvement may benefit from respiratory muscle training.

[Inspiratory muscle training combined with general exercise reconditioning in chronic obstructive pulmonary disease].

In a controlled clinical trial, we compared the effect of 6 months of specific inspiratory muscle training combined with general exercise reconditioning, with that of general exercise reconditioning alone. We measured the effects of the 2 regimens on inspiratory muscle strength, endurance, and exercise performance in patients with chronic obstructive pulmonary disease (COPD), 2 groups of 10 patients each. Inspiratory muscle strength (expressed as the PImax at RV) increased significantly from 43.2 +/- 3.0 to 67.8 +/- 2.9 cm H2O (p < 0.0001) and respiratory muscle endurance (expressed as the relationship between PmPeak, the pressure achieved with the heaviest load tolerated for at least 60 sec, and PI max) increased significantly from 60.2 +/- 2.5 to 85.6 +/- 2.8% (p < 0.001) in the first group (combined treatment). After the 6-month training period, in both groups there were significant increases in 12-minute walk and endurance work time at 2/3 of Wmax (maximal work each subject achieved on a progressive bicycle exercise test of maximum work load). However, those in the first group showed significantly greater improvement in distance walked and endurance time than the others. We conclude that specific inspiratory muscle training for 6 months improves inspiratory muscle strength and endurance in patients with COPD. This training, combined with general exercise reconditioning, also results in improvement in exercise tolerance significantly greater than that of general exercise reconditioning alone.

[Aortopulmonary fistula due to failed graft for aortic aneurysm].

Hemoptysis originating from an aortobronchial fistula is uncommon. This fistulous connection between the aorta and the lung usually results from a preexisting thoracic-aortic aneurysm, and is uniformly fatal when left untreated. However, with early diagnosis the survival rate exceeds 80%. The case of an aortobronchial fistula in a young alcoholic, 2 years after aortic aneurysmectomy, is presented. He was admitted with symptoms suggesting upper gastrointestinal bleeding, allegedly related to alcohol abuse. He died of a sudden, massive hemoptysis 5 days after admission. An aortobronchial fistula was found on autopsy. To diagnose aortobronchial fistula, a high index of suspicion is necessary. It should be considered in patients with hemoptysis after repair of a thoracic aneurysm.

The combined effect of nifedipine and sodium cromoglycate on the airway response to inhaled hypertonic saline in patients with bronchial asthma.

The combined effect of oral nifedipine and aerosolized sodium cromoglycate on the airway response to inhaled sodium chloride at increasing concentrations was randomly studied in 10 patients with bronchial asthma. Nifedipine (20 mg) protected the airways in 6 of the 10 patients, and sodium cromoglycate (20 mg) in all the 10 patients. Following both drugs, the airway response to hypertonic saline was further reduced when compared to each drug on its own. It is concluded that the combination of nifedipine with sodium cromoglycate might be of benefit in the treatment of difficult asthmatic patients.