Chest
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Respiratory infections remain the most common reason why patients seek medical care in ambulatory and hospital settings, and they are the most frequent precursor of sepsis. In light of the limitations of clinical signs and symptoms and traditional microbiologic diagnostics for respiratory infections, blood biomarkers that correlate with the presence and extent of bacterial infections may provide additional useful information to improve diagnostic and prognostic efforts and help with therapeutic decisions in individual patients. A growing body of evidence supports the use of procalcitonin (PCT) to differentiate bacterial from viral respiratory diagnoses, to help risk stratify patients, and to guide antibiotic therapy decisions about initial need for, and optimal duration of, therapy. ⋯ As with any other laboratory test, PCT should not be used on a stand-alone basis. Rather, it must be integrated into clinical protocols, together with clinical, microbiologic data and with results from clinical risk scores. The aim of this review is to summarize recent evidence about the usefulness of PCT in patients with lower respiratory tract infections and to discuss the potential benefits and limitations of this marker when used for clinical decision making.
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Pneumothorax in critically ill patients remains a common problem in the ICU, occurring in 4% to 15% of patients. Pneumothorax should be considered a medical emergency and requires a high index of suspicion, prompt recognition, and intervention. The diagnosis of pneumothorax in the critically ill patient can be made by physical examination findings or radiographic studies including chest radiographs, ultrasonography, or CT scanning. ⋯ If there is suspicion for tension pneumothorax, immediate decompression and drainage should be performed. With widespread use of CT scanning, there have been more occult pneumothoraces diagnosed, and the most recent literature suggests that drainage is preferred. In patients with a persistent air leak or failure of the lung to expand, current guidelines suggest that an early thoracic surgical consultation be requested within 3 to 5 days.
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Maintaining an airway clear of inhaled particles, pathogens, and cellular debris is paramount for lung homeostasis. In healthy individuals, the phagocytes of the innate immune system act as sentinels to patrol the airway and ensure sterility. However, in airways diseases, including asthma, COPD, and cystic fibrosis, there is a propensity for bacterial colonization that may contribute to disease worsening. ⋯ In asthma and other airways diseases, there are also reports of defective phagocytosis of bacterial pathogens, although the relevance to disease pathophysiology is not understood. Oxidative stress is emerging as a common mechanism that may be altering both macrophage and neutrophil functions that can be reversed by various antioxidant strategies. The identification of this and other mechanisms underlying phagocyte dysfunction may present novel therapeutic opportunities for the treatment of many of these intractable diseases and improve patient morbidity and mortality.
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The treatment of cough is a significant clinical unmet need because there is little evidence that current therapies are effective. Based on evidence supporting a role for N-methyl D-aspartate receptors (NMDARs) in cough, we hypothesized that memantine, a low-affinity, uncompetitive NMDAR channel blocker in routine use for the treatment of Alzheimer disease, could be an effective, well-tolerated, antitussive therapy. The aim of this study was to establish preclinical evidence that memantine has antitussive effects. ⋯ This study illustrates that memantine has marked antitussive effects in guinea pigs, most likely mediated through NMDAR channel blockade. Memantine, therefore, has the potential to be a safe, effective, and well-tolerated antitussive agent.
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Comparative Study
Quantification of cardiorespiratory fitness in healthy nonobese and obese men and women.
The quantification and interpretation of cardiorespiratory fitness (CRF) in obesity is important for adequately assessing cardiovascular conditioning, underlying comorbidities, and properly evaluating disease risk. We retrospectively compared peak oxygen uptake (VO(2)peak) (ie, CRF) in absolute terms, and relative terms (% predicted) using three currently suggested prediction equations (Equations R, W, and G). ⋯ Traditional methods of reporting VO(2)peak do not allow adequate assessment and quantification of CRF in obese adults. Predicted VO(2)peak does allow a normalized evaluation of CRF in the obese, although care must be taken in selecting the most appropriate prediction equation, especially in women. In general, otherwise healthy obese are not grossly deconditioned as is commonly believed, although CRF may be slightly higher in nonobese subjects depending on the uniqueness of the prediction equation.