Seminars in respiratory and critical care medicine
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Semin Respir Crit Care Med · Apr 2015
ReviewNontuberculous mycobacteria in cystic fibrosis and non-cystic fibrosis bronchiectasis.
Increasing numbers of cystic fibrosis (CF) and non-CF bronchiectasis patients are affected by pulmonary nontuberculous mycobacteria (NTM) infection worldwide. Two species of NTM account for up to 95% of the pulmonary NTM infections: Mycobacterium avium complex (MAC) and Mycobacterium abscessus complex (MABSC). Diagnosis of pulmonary NTM infection is based on criteria specified in the 2007 American Thoracic Society/Infectious Disease Society of America (ATS/IDSA) guidelines. ⋯ Recurrence rates of NTM after initial successful treatment remain high, likely due to nonmodifiable risk factors raising the question of whether secondary prophylaxis is feasible. More rapid and readily available methods for detecting inducible macrolide resistance and better in vitro susceptibility testing methods for other drugs that correlate with clinical responses are needed. This is crucial to identify more effective regimens of existing drugs and for development of novel drugs for NTM infection.
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Semin Respir Crit Care Med · Apr 2015
ReviewImaging in cystic fibrosis and non-cystic fibrosis bronchiectasis.
Bronchiectasis is defined as a permanent and progressive dilation of the airways, typically as a result of inflammation, infection, and subsequent repair. It typically presents with chronic cough, suppurative sputum production, and airway dilation. High-resolution computed tomography (HRCT) is now well established as the primary imaging tool for its investigation. ⋯ This is particularly relevant in a pulmonary disease such as bronchiectasis, which often undergoes serial HRCT surveillance in contemporary practice. Several new CT clinical applications in bronchiectasis have been recently advanced, and CT is now being increasingly incorporated into investigative algorithms to assess bronchiectasis treatment effects. In this review, we assess the latest imaging features of CF and non-CF bronchiectasis, discuss radiation dose reducing methods and technology of the latest scanners, describe recent CT clinical applications, and explore the use of CT as a treatment surrogate in CF and non-CF bronchiectasis.
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Carbapenemase-producing Enterobacteriaceae (CPE) were almost nonexistent up to the 1990s, but are today encountered routinely in hospitals and other healthcare facilities in many countries including the United States. KPC-producing Klebsiella pneumoniae was the first to emerge and spread globally and is endemic in the United States, Israel, Greece, and Italy. Recently, NDM-producing Enterobacteriaceae and OXA-48-producing K. pneumoniae appear to be disseminating from South Asia and Northern Africa, respectively. ⋯ To obtain the maximal benefit from the limited options available, dosing of antimicrobial agents should be optimized based on pharmacokinetic data, especially for colistin and carbapenems. In addition, multiple observational studies have associated combination antimicrobial therapy with lower mortality compared with monotherapy for these infections. The outcomes appear to be especially favorable when patients are treated with a carbapenem and a second agent such as colistin, tigecycline, and gentamicin, but the best approach is yet to be defined.
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Semin Respir Crit Care Med · Feb 2015
ReviewStenotrophomonas, achromobacter, and nonmelioid burkholderia species: antimicrobial resistance and therapeutic strategies.
Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and nonmelioid Burkholderia species, namely, Burkholderia cepacia complex, collectively are a group of troublesome nonfermenters. Although not inherently virulent organisms, these environmental Gram negatives can complicate treatment in those who are immunocompromised, critically ill in the intensive care unit and those patients with suppurative lung disease, such as cystic fibrosis. ⋯ Despite trimethoprim-sulfamethoxazole often being the mainstay of treatment, resistance is widely encountered, and alternative regimens, including combination therapy, are often used. This review will highlight the important aspects and unique challenges that these three nonfermenters pose, and, in the absence of clinical outcome data, our therapeutic recommendations will be based on reported antimicrobial susceptibility and pharmacokinetic/pharmacodynamic profiles.