Annals of the American Thoracic Society
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Risk stratification is a mainstay in the care of cardiac and pulmonary disorders, as the identification of adverse outcomes helps provide measures to improve survival and quality of life. The cardiopulmonary exercise test is a useful prognostic tool in the clinical evaluation of several pathological conditions, such as heart diseases, respiratory disorders, and pulmonary hypertension. If not contraindicated, a cardiopulmonary exercise test should always be performed and integrated with clinical, laboratory, and hemodynamic parameters to better stratify patient risk. ⋯ The prognostic role of the cardiopulmonary exercise test in heart failure is amplified when included in multiparametric risk stratification methodology, currently considered the best method to assess patient outcome. In respiratory disorders and in pulmonary hypertension, cardiopulmonary exercise test parameters, focusing on ventilatory performance during exercise, may help evaluate the risk of adverse events. Finally, the cardiopulmonary exercise test may help define the presence of coexisting cardiac and respiratory disorders, a combination that leads to increased rates of disability and mortality.
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Endobronchial ultrasound (EBUS) has transformed mediastinal staging in lung cancer. A systematic approach, beginning with lymph nodes contralateral to the primary tumor (N3), is considered superior to selective sampling of radiographically abnormal nodes. However, the extent to which this recommendation is followed in practice remains unknown. ⋯ General pulmonologists and pulmonary fellows were less likely than interventional pulmonologists to perform appropriate EBUS staging. In addition, the lack of concordance between self-confidence and appropriate staging performance among noninterventionists signals a need for improved dissemination of guidelines for EBUS-guided mediastinal staging.
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Acetazolamide is a carbonic anhydrase (CA) inhibitor sometimes used as a respiratory stimulant for patients with chronic obstructive pulmonary disease (COPD) with the goal of improving oxygenation, reducing carbon dioxide retention, and aiding liberation from mechanical ventilation and/or attempting to correct a metabolic alkalosis. However, the net effect of CA inhibition is multifactorial and complex, because CA is inhibited in many tissues that may negatively affect the patient with lung disease. The full impact of acetazolamide and other CA inhibitors depends critically on dosing, age, and pulmonary, renal, hepatic, hematological, and respiratory muscle function and reserves. ⋯ There are very few studies specifically designed to address the population with severe COPD, as such patients were frequently excluded from trials. We therefore discuss the complexity of CA inhibition and its potential benefits and dangers and describe ways in which the pathophysiology of patients with severe COPD puts them at considerable risk for serious adverse consequences. We offer guidance on the careful and rational use of acetazolamide in patients with respiratory disorders.
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Randomized Controlled Trial
Effect of 4-Aminopyridine on Genioglossus Muscle Activity during Sleep in Healthy Adults.
The reduction in upper airway muscle activity from wakefulness to sleep plays a key role in the development of obstructive sleep apnea. Potassium (K+) channels have been recently identified as the downstream mechanisms through which hypoglossal motoneuron membrane excitability is reduced both in non-rapid eye movement (NREM) sleep and REM sleep. In animal models, the administration of 4-aminopyridine (4-AP), a voltage-gated K+ channel blocker, increased genioglossus activity during wakefulness and across all sleep stages. ⋯ A single dose of 4-AP 10 mg extended release showed only a small increase in tonic EMGGG during REM sleep in this group of healthy subjects. We speculate that a higher dose of 4-AP may further increase EMGGG. However, given the potentially severe, dose-related adverse effects of this drug, including seizures, the administration of 4-AP does not appear to be an effective strategy to increase genioglossus activity during sleep in humans. Clinical Trial registered with clinicaltrials.gov (NCT02656160).
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Nontuberculous mycobacteria (NTM) are a diverse group of environmental organisms that infrequently cause human disease. Understanding of the epidemiologic and clinical characteristics associated with NTM disease is needed to refine diagnostic and treatment strategies, particularly among the less commonly isolated species. ⋯ Isolation of NTM varied by geographic region of origin and location within Washington State. Several clinical risk factors were specific to individual species. Comorbid conditions were common in patients with and without mycobacterial disease. Among patients with one of the studied organisms, there was a high mortality rate more frequently related to comorbid conditions than to mycobacterial disease.