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The 6-min walk test, commonly used to assess exercise capacity and response to therapy in pulmonary arterial hypertension (PAH), has many well-described limitations. Sedentary time is associated with adverse cardiovascular outcomes and reduced quality of life, and measuring sedentary time and physical activity using accelerometry is another potential way to quantify exercise capacity in PAH. Whether sedentary time is different in patients with PAH vs control subjects is unknown. ⋯ Sedentary time is increased in patients with PAH and may lead to increased risk for metabolic and cardiovascular morbidity. Quantitation of daily activity and sedentary time using accelerometry may be a novel end point for PAH management and clinical trials.
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Approximately 40% of patients in medical ICUs require mechanical ventilation (MV). Approximately 20% to 25% of these patients will encounter difficulties in discontinuing MV. Multiple studies have suggested that MV has an unloading effect on the respiratory muscles that leads to diaphragmatic atrophy and dysfunction, a process called ventilator-induced diaphragmatic dysfunction (VIDD). VIDD may be an important factor affecting when and if MV can be discontinued. A sensitive and specific diagnostic test for VIDD could provide the physician with valuable information that might influence decisions regarding extubation or tracheostomy. The purpose of this study was to quantify, using daily sonographic assessments, the rate and degree of diaphragm thinning during MV. ⋯ Sonographic assessment of the diaphragm provides noninvasive measurement of diaphragmatic thickness and the degree of diaphragm thinning in patients receiving MV. Our data show that diaphragm muscle thinning starts within 48 h after initiation of MV. However, it is unclear if diaphragmatic thinning correlates with diaphragmatic atrophy or pulmonary function. The relationship between diaphragm thinning and diaphragm strength remains to be elucidated.
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Identification of sleep-disordered breathing (SDB) using questionnaires is critical from a clinical and research perspective. However, which questions to use and how well such questionnaires perform has thus far been fraught with substantial uncertainty. We aimed at delineating the usefulness of a set of questions for identifying pediatric SDB. ⋯ As a result, the set of six hierarchically arranged questions will aid the screening of children at high risk for SDB but cannot be used as the sole diagnostic approach.
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Propensity scores have been proposed as a method of equating groups at baseline, which is a problem, especially in studies that do not use randomization. This article discusses some difficulties with the technique that may jeopardize the findings if users (and readers) are not aware of these problems.
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Lymphangiogenesis responds to tissue injury as a key component of normal wound healing. The development of fibrosis in the idiopathic interstitial pneumonias may result from abnormal wound healing in response to injury. We hypothesize that increased lymphatic vessel (LV) length, a marker of lymphangiogenesis, is associated with parenchymal components of the fibroblast reticulum (organizing collagen, fibrotic collagen, and fibroblast foci), and its extent correlates with disease severity. ⋯ Severity of disease in UIP and NSIP is associated with increased LV length and is strongly associated with components of the fibroblast reticulum, namely organizing and fibrotic collagen, which supports a pathogenic role of LVs in these two diseases. Furthermore, the absence of definable differences between UIP and NSIP suggests that LVs are a unifying mechanism for the development of fibrosis in these fibrotic lung diseases.