3615. The evolving role of exercise testing prior to lung resection.
Exercise testing prior to lung resection has long and honored tradition. It began as a test of tolerance using simple techniques such as stair climbing. This was followed by aggressive and invasive protocols using right cardiac catheterization in the search for pulmonary hypertension. More recently, measurement of VO2 with exercise has been reported to predict both postoperative mortality and survivable morbidity. Exercise testing holds promise as a noninvasive test to predict the physiologic outcome from lung resection. Significant questions remain concerning the pathophysiologic mechanisms responsible for an abnormal result and who should be denied thoracotomy based on these results.
3617. Magnetic resonance for evaluation of the thorax.
Evaluation of diseases in the chest by MR is continually evolving. Early studies showed the potential of the technique for imaging the mediastinal and hilar structures and for demonstrating the normal anatomy of the thorax on sagittal, coronal, and transverse MR images. As more data have been compiled, investigators have compared MR to computed tomography for its ability to assess mediastinal and hilar adenopathy and masses, bronchogenic carcinoma and other pulmonary parenchyma lesions, and for assessment of the pulmonary vascularity. MR has been shown in these situations generally to provide equivalent information to that provided by computed tomography. MR, compared to computed tomography, is still in its infancy in regard to the length of time of its availability and in relation to the MR technology for obtaining images. MR is a technique that has wide variation as to type of image quality obtained depending upon the MR system utilized and the pulse sequence utilized. Because of the diverse nature of potential variables for imaging, many times the images are not equal in quality. As a consequence of this significant variability, the data in the literature are divergent on the precise utility of MR. Although the recommended use of MR may change rapidly, the current feeling is that MR should be used as a procedure complementary to computed tomography in those patients with allergy to iodinated contrast material and to aid in defining equivocal lesions as seen on computed tomography, such as small central hilar bronchogenic carcinomas.
3618. Increased muscle efficiency and sustained benefits in an outpatient community hospital-based pulmonary rehabilitation program.
Previous reports of pulmonary rehabilitation programs have demonstrated improvement in exercise capacity in subjects with disabling pulmonary disease. However, the cost-effectiveness, benefits to outpatients in a community setting, durability of these improvements, and mechanism of improved exercise capacity remain unclear. Forty-four patients with an average FEV1 of 33 +/- 4 percent of predicted completed a six-week long period of supervised treadmill exercise, as well as a continuing home program. Twenty percent had previously unsuspected cardiac disease discovered through the program, while 36 percent had previously unsuspected exercise desaturation. Cardiopulmonary stress testing before and after the program revealed a 73 +/- 16 percent improvement in aerobic capacity (METs peak [power]) and a 250 +/- 78 percent improvement in endurance (MET-min [work]). No significant change was seen in VE max, HR max, FEV1, or the degree of exercise desaturation. Only a small improvement was noted in VO2 max (15 +/- 8 percent) and O2 pulse (16 +/- 8 percent), suggesting that most of the improvement was due to improved muscle efficiency. Follow-up testing at 12 +/- 3 months in 24 subjects revealed that 89 +/- 7 percent of the peak exercise performance was maintained. The cost of the basic program was +800. The results demonstrated that an outpatient community hospital pulmonary rehabilitation program can accomplish substantial exercise capacity improvement with sustained benefits in a cost-effective manner.
3619. Corticosteroids in the treatment of tuberculous pleurisy. A double-blind, placebo-controlled, randomized study.
A prospective, double-blind, randomized study of the role of corticosteroids in the treatment of tuberculous pleurisy was performed in 40 patients. All patients received adequate antituberculosis chemotherapy (isoniazid, 300 mg/day; rifampin, 450 mg/day; ethambutol, 20 mg/kg/day) for more than nine months. They were randomly assigned to take prednisolone 0.75 mg/kg/day orally or placebo for the initial treatment, which was tapered gradually for the next two to three months. Twenty-one were treated with steroids and 19 were given a placebo. The two groups were identical with regard to age, sex, duration from onset of symptoms to diagnosis, and initial amount of pleural effusion. The mean duration from symptoms (fever, chest pain, dyspnea) to relief was 2.4 days in the steroid-treated group, and 9.2 days in the placebo group (p less than 0.05). Complete reabsorption of pleural effusion occurred an average of 54.5 days in the steroid-treated group and 123.2 days in the placebo group (p less than 0.01). The development of residual pleural thickening was not influenced by the administration of corticosteroids. No serious side effects were noted during the treatment in either group. We conclude that the administration of corticosteroids, in conjunction with antituberculosis chemotherapy, will resolve the clinical symptoms more quickly and hasten the absorption of pleural effusion in patients with tuberculous pleurisy.
3620. In vivo right heart thrombus. Precursor of life-threatening pulmonary embolism.
This report describes three cases of massive mobile right heart thrombus and reviews the available literature to better define the pathophysiology, natural history and most appropriate therapy of the syndrome. The clinical presentation of most patients has been severe cardiopulmonary dysfunction and the diagnosis has been made by echocardiographic study. The most likely source of these cardiac thrombi is the large systemic veins. The associated mortality risk is very high. Therapy has, heretofore, been individualized. Embolectomy has been most favored, with a survival rate of 80 percent. The role of thrombolytic therapy remains to be delineated. Therapy should, however, be initiated rapidly because of the precipitous nature of the mortality risk.
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