American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Sep 2000
Rotation and restricted use of antibiotics in a medical intensive care unit. Impact on the incidence of ventilator-associated pneumonia caused by antibiotic-resistant gram-negative bacteria.
To test the hypothesis that a new program of antibiotic strategy control can minimize the incidence of ventilator-associated pneumonia (VAP) caused by potentially antibiotic-resistant microorganisms, we performed a prospective before-after study in 3, 455 patients admitted to a single intensive care unit over a 4-yr period. Regarding the bacterial ecology and the increasing antimicrobial resistance in our medical intensive care unit (MICU), we decided to vary our choice of empiric and therapeutic antibiotic treatment, with a supervised rotation, and a restricted use of ceftazidime and ciprofloxacin, which were widely prescribed before this scheduled change. For all patients, VAP was diagnosed based on the results of quantitative culture of bronchoalveolar lavage specimens (>/= 10(4) cfu/ml). ⋯ The percentage of methicillin-sensitive Staphylococcus aureus increased significantly from 40% to 60% of S. aureus responsible for VAP. These results suggest that a new strategy of antibiotics use could be an efficient means to reduce the incidence of VAP caused by antibiotic-resistant bacteria. Nevertheless, further studies are needed to validate these data.
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Am. J. Respir. Crit. Care Med. · Sep 2000
Comparative StudyAirway inflammation in nonobstructive and obstructive chronic bronchitis with chronic haemophilus influenzae airway infection. Comparison with noninfected patients with chronic obstructive pulmonary disease.
Nonencapsulated Haemophilus influenzae often causes chronic infections of the lower respiratory tract in both nonobstructive and obstructive chronic bronchitis. We assessed airway inflammation in clinically stable, chronically H. influenzae-infected patients with nonobstructive (CB-HI, n = 10) and in patients with obstructive chronic bronchitis (COPD-HI, n = 10) by analyses of the sol phase of spontaneously expectorated sputum (SSP). As compared with the CB-HI group, the COPD-HI group had significantly higher (p < 0.05) levels of myeloperoxidase (MPO) and tumor necrosis factor (TNF)-alpha in their SSP, whereas the degree of plasma protein leakage (SSP-to-serum ratio of plasma proteins) and the levels of interleukin (IL)-8, secretory IgA, and lactoferrin were similar in the two groups. ⋯ This finding, however, does not exclude an exaggerated TNF-alpha response to infection or another stimulus in the airways of COPD patients. The SSP levels of MPO and IL-8, and the degree of plasma protein leakage in the COPD-HI group, were retrospectively compared with and found significantly higher than those of noninfected COPD patients, suggesting a more marked inflammatory response in COPD-HI. Whether this reflects a direct cause-and-effect relationship should be addressed in a future long-term prospective study involving repeated measurements in the same patients.
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Am. J. Respir. Crit. Care Med. · Sep 2000
Induced sputum inflammatory mediator concentrations in eosinophilic bronchitis and asthma.
Eosinophilic bronchitis is a common cause of chronic cough, which like asthma is characterized by sputum eosinophilia, but in contrast to asthma there is no variable airflow obstruction or airway hyperresponsiveness. Our hypothesis was that the differences in airway pathophysiology maybe due to less active airway inflammation in eosinophilic bronchitis, with reduced release of important effector mediators. We measured the concentration of various proinflammatory mediators in induced sputum cell-free supernatant in eight patients with eosinophilic bronchitis, 17 patients with asthma matched for sputum eosinophil count, and 10 normal subjects. ⋯ Sputum cys-LT and ECP were a mean (95% CI) 1.6-fold (1.1, 2.5) and 6.4-fold (1.4, 28) higher in eosinophilic bronchitis and 1.9-fold (1.3, 2.9) and 7.7-fold (1.2, 46) higher in asthma compared with that in control subjects (geometric mean, 5.9 and 95 ng/ml, respectively). In eosinophilic bronchitis the mean concentration of sputum PGD(2) (0.79 ng/ml) and histamine (168 ng/ml) were significantly higher than in asthma (mean absolute difference in PGD(2) concentration, 0.47 ng/ml [95% CI, 0.19 to 0. 74] and mean-fold difference in histamine concentration, 6.7 [95% CI 1.7 to 26]) and normal subjects (0.64 ng/ml [0.36 to 0.90] and 11-fold [3.3 to 36]), respectively. In conclusion, eosinophilic bronchitis is associated with active airway inflammation with increased release of vasoactive and bronchoconstrictor mediators.
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Am. J. Respir. Crit. Care Med. · Sep 2000
Computed tomographic measurements of airway dimensions and emphysema in smokers. Correlation with lung function.
Chronic obstructive pulmonary disease (COPD) is characterized by the presence of airflow obstruction caused by emphysema or airway narrowing, or both. Low attenuation areas (LAA) on computed tomography (CT) have been shown to represent macroscopic or microscopic emphysema, or both. However CT has not been used to quantify the airway abnormalities in smokers with or without airflow obstruction. ⋯ The CT measurements revealed that a decreased FEV(1) (%predicted) is associated with an increase of airway wall area and an increase of emphysema. Although both airway wall thickening and emphysema (LAA) correlated with measurements of lung function, stepwise multiple regression analysis showed that the combination of airway and emphysema measurements improved the estimate of pulmonary function test abnormalities. We conclude that both CT measurements of airway dimensions and emphysema are useful and complementary in the evaluation of the lung of smokers.
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Am. J. Respir. Crit. Care Med. · Sep 2000
Randomized Controlled Trial Clinical TrialContinuous positive airway pressure during fiberoptic bronchoscopy in hypoxemic patients. A randomized double-blind study using a new device.
Fiberoptic bronchoscopy (FOB) may worsen oxygenation and clinical status in severely hypoxemic patients. We conducted a prospective, randomized double-blind trial to compare the delivery of continuous positive airway pressure (CPAP) as a tool for maintaining oxygenation during FOB, to the delivery of oxygen only. Thirty consecutive patients who needed FOB for diagnostic purposes were enrolled. ⋯ Arterial blood gases 15 min after FOB showed that Pa(O(2)) had increased in the CPAP group and decreased in the Oxygen group (DeltaPa(O(2)) = +10.5% +/- 16.9 versus -15% +/- 16.6, p = 0.01). Five patients in the Oxygen group, but none in the CPAP group, developed respiratory failure in the 6 h after FOB and required ventilatory assistance (p = 0.03). We conclude that in hypoxemic patients, the use of a new CPAP device during FOB allowed minimal alterations in gas exchange and prevented subsequent respiratory failure.