Respiratory care
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Exercise capacity assessed by cardiopulmonary exercise testing is usually measured by peak oxygen consumption (VO2). However, not uncommonly, patients achieve a relatively higher work load (peak work) compared to their peak VO2. In these situations it is difficult to know which parameter to use in assessing exercise capacity. The purpose of this study was to determine whether there are distinguishing physiological characteristics of patients with discordance between percent-of-predicted peak work versus peak VO2, in order to understand how to use these measurements in interpreting exercise capacity. ⋯ The observation that there are distinguishing physiological features between those who have a higher peak work and those who have higher peak VO2 provides insight into the underlying processes determining maximal exercise capacity.
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The diffusion capacity of the lung for carbon monoxide (DLCO) is a good marker of disease severity in patients with idiopathic interstitial pneumonia, and is associated with oxygen saturation; however, little is known about DLCO in systemic sclerosis patients with interstitial lung disease. We studied potential predictors of exercise-induced oxygen desaturation in patients with systemic sclerosis. ⋯ The factor underlying exercise-induced oxygen desaturation appeared to be reduced percent-of-predicted DLCO, which was useful as a predictor in over 80% of the subjects.
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Randomized Controlled Trial
Effect of Training on Inspiratory Load Compensation in Weaned and Unweaned Mechanically Ventilated ICU Patients.
While inspiratory muscle weakness is common in prolonged mechanical ventilation, inspiratory muscle strength training (IMST) can facilitate strengthening and ventilator weaning. However, the inspiratory load compensation (ILC) responses to threshold loads are not well characterized in patients. We retrospectively compared ILC responses according to the clinical outcomes of IMST (ie, maximum inspiratory pressure [PImax], weaning outcome), in difficult-to-wean ICU patients. ⋯ Flow ILC at a threshold load of 10 cm H2O in ventilated, tracheostomized subjects positively correlated with PImax. Although PImax improved in both groups, the flow and volume ILC responses of the weaned subjects were more robust, both before and after IMST. The results suggest that ILC response is different in weaned and unweaned subjects, reflecting dynamic inspiratory muscular efforts that could be influential in weaning.
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Elderly patients may be at greater risk for misdiagnosis and inappropriate treatment as a consequence of pulmonary function test underutilization and tests being conducted with low quality expectations. This study sought to determine if elderly patients are able to achieve both spirometry and diffusion capacity (DLCO) quality scores comparable to a younger adult population. ⋯ Elderly patients referred to a hospital-based pulmonary function test lab can be expected to achieve spirometry and DLCO quality scores comparable to younger adult patients.
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Peripheral muscle dysfunction is a common finding in patients with COPD; however, the structural adaptation and functional impairment of the upper and lower limb muscles do not seem to be homogenous. We compared muscle fatigue and recovery time between 2 representative muscles: the middle deltoid and the quadriceps femoris. ⋯ Subjects with COPD had a higher fatigability of a representative upper limb muscle (middle deltoid) than a lower limb muscle (quadriceps femoris).