American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Dec 2016
ReviewTranslational Aspects of the Human Respiratory Virome.
Despite the dominant role of community-acquired respiratory viruses as etiological agents of disease, there has been little focus to date on the translation of rapidly developing diagnostic modalities, such as next-generation sequencing techniques in the examination of lower respiratory tract samples. When applied, these techniques should inform strategies to both understand the nexus between health and disease states of the respiratory virome, and drive a paradigm shift in how the practicing pulmonologist views the conceptual framework of respiratory infections. The lower respiratory tract was once thought to be a sanctuary site from microbiological colonization owing to the efficacy of upper airway-protective mechanisms and the host mucosal barrier function of the lower airways, combined with both innate and adaptive immune responses. ⋯ Hence, it is now timely to revise our thinking regarding the constituents, diversity, and changing nature of the respiratory virome in health and disease. One area worthy of focus is the interface between community-acquired respiratory viruses and the respiratory virome to better understand the dynamics in acute infection, as well as the factors that may lead to viral persistence and chronic disease. Given recent advances in metagenomics, the tools are now at hand to accomplish these goals.
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Am. J. Respir. Crit. Care Med. · Dec 2016
ReviewTranspulmonary Pressure: The Importance of Precise Definitions and Limiting Assumptions.
Recent studies applying the principles of respiratory mechanics to respiratory disease have used inconsistent and mutually exclusive definitions of the term "transpulmonary pressure." By the traditional definition, transpulmonary pressure is the pressure across the whole lung, including the intrapulmonary airways, (i.e., the pressure difference between the opening to the pulmonary airway and the pleural surface). However, more recently transpulmonary pressure has also been defined as the pressure across only the lung tissue (i.e., the pressure difference between the alveolar space and the pleural surface), traditionally known as the "elastic recoil pressure of the lung." Multiple definitions of the same term, and failure to recognize their underlying assumptions, have led to different interpretations of lung physiology and conclusions about appropriate therapy for patients. ⋯ These misconceptions include assertions that normal pleural pressure must be negative (subatmospheric) and that a pressure in the pleural space may not be substantially positive when a subject is relaxed with an open airway. We urge specificity and uniformity when using physiological terms to define the physical state of the lungs, the chest wall, and the integrated respiratory system.
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Am. J. Respir. Crit. Care Med. · Dec 2016
ReviewChronic Obstructive Pulmonary Disease and Cardiac Diseases: An Urgent Need for Integrated Care.
Chronic obstructive pulmonary disease (COPD) is a global health issue with high social and economic costs. Concomitant chronic cardiac disorders are frequent in patients with COPD, likely owing to shared risk factors (e.g., aging, cigarette smoke, inactivity, persistent low-grade pulmonary and systemic inflammation) and add to the overall morbidity and mortality of patients with COPD. The prevalence and incidence of cardiac comorbidities are higher in patients with COPD than in matched control subjects, although estimates of prevalence vary widely. ⋯ The therapeutic management of patients with cardiac and pulmonary comorbidities may be similarly challenging: bronchodilators may have cardiac side effects, and, vice versa, some cardiac medications should be used with caution in patients with lung disease. The aim of this review is to summarize the evidence of the relationship between COPD and the three most frequent and important cardiac comorbidities in patients with COPD: ischemic heart disease, heart failure, and atrial fibrillation. We have chosen a practical approach, first summarizing relevant epidemiological and clinical data, then discussing the diagnostic and screening procedures, and finally evaluating the impact of lung-heart comorbidities on the therapeutic management of patients with COPD and heart diseases.