They then used various kinds of high-resolution ...

For more than four decades, we know that peripheral airway resistance increases with emphysema. But it is unclear what changes lead to an increase of the resistance. Take just a narrow airway, or they are destroyed at all? Without the technology to address this issue, it remains virtually unanswered. Until now. In this regard weekBЂ ™'s NEJM, John Mc-Don and colleagues used the field of transplantation of lungs and high-resolution CT to BЂ

"and conclude that the small airways really destroyed in patients with chronic obstructive pulmonary disease (COPD) . To conduct this study, the authors studied the lives of patients eksplantirovannyh pulmonary emphysema and healthy intended for transplantation. They included 78 patients with COPD who had to undergo multiple detector CT in any case under investigation for prevention of lung cancer. Patients had varying degrees of severity. Most of them were in the late 50's and 60's, with more than 40 pack-years of smoking. b In addition to this patient pool, the authors collected data on 12 eksplantirovannyh lung in patients undergoing transplantation of emphysema and four control lungs, which were intended for transplantation, but went unmatched. When using live patients and lightweight designs, they can learn the light at two different levels of permission. For patients with COPD, which are high resolution, CT, the authors quantified the number of small airways (defined as the measurement of respiratory tract 2-2. 5 mm internal diameter). They then used various kinds of high-resolution CT, which can not be used in clinical settings to get even closer view of the pulmonary parenchyma, this time donated samples of light. Lung samples were frozen, and the authors were able to attend the branching of the smallest airways to calculate the number and diameter of terminal bronchioles. What they found that patients with COPD were less worse and have small airways. Indeed, eksplantirovannyh lungs (in patients with emphysema is transplant) was 72 to 89% less terminal bronchioles (bronchioles that do not end in alveoli) than controls. to patients with less severe COPD also had less and have smaller airways. While it was not possible to determine whether there is a small loss of airway prior to emphysematous destruction of alveolar air space, the authors hypothesized that small airways were actually lost in the first place. It should be noted that the authors recognize that itBЂ ™ s possible CT was not sufficiently sensitive instrument, and the airways were not removed as a whole, but it really comes down to the gap is too small to be noticed CT. In any case, functional impairment, most likely the same. They concluded: BЂњThere widespread narrowing and loss of lower respiratory tract before the emphysematous destructionBЂ | This process readily explains the observed increaseBЂ | in small airway resistance in patients with COPD. BЂ "

B, Wayne Mitzner, physiologist who studies the lungs Johns Hopkins says that this study should change the way we think about and identify emphysema, and also offers a potential mechanism to explain airway destruction. Based on McDonough and others alBЂ ™ s findings, he argues that in emphysema itBЂ ™ really small airways that are affected first, not the alveoli. Respiratory tract becomes inflamed, narrowed and eventually eliminated. After itBЂ ™ s cut, elastic fibers that normally support the alveoli free support them and can no longer maintain the alveoli. Thus, the alveolar wall collapses and folds, forming bullae seen in COPD. Although thereBЂ ™ no clear clinical correlation, this mechanism can offer is time for COPD patientsBЂ "when the airway is narrowed, but not destroyed BЂ" where changes in behavior or medication administration could improve their lung function. Indeed,

Journal of Jorgen Vestbo and colleagues looked at the rate of change in FEV1 over time in patients with COPD, and found as part of the story diseaseBЂ ™ s, some patients saw improvement in their lung function. ItBЂ ™ is possible that by taking these studies together, those patients whose airways narrowed, but were not removed at the time they quit smoking cigarettes, for example. Is it really so McDonoughBЂ ™ study brings us one step closer to understanding the process that mostly unnoticed until it is irreversible. BЂњThis destruction is quiet, very far in the lung periphery, BЂ "says pulmonologist and chief editor of the NEJM, Dr. Jeffrey Drazhen. Q: How can this physiological step forward in understanding points the way to better treatment of COPD? Tags:,,

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