The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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Weaning from mechanical ventilation is a period of transition from total ventilatory support to spontaneous breathing. It represents a relevant clinical problem because as many as 25% of intubated and mechanically-ventilated critically ill patients will need a progressive withdrawal from artificial ventilatory support. From a clinical standpoint, it is very important to recognize as soon as possible when a patient is ready to be weaned. ⋯ Different ventilatory techniques can be used to wean these patients from mechanical ventilation. Up to now, the most efficient techniques seem to be pressure support ventilation and once daily trials of T-piece interspersed with conventional volume assist-control ventilation. Finally, knowledge-based system applied to modern microprocessor mechanical ventilators can help in the process of weaning by automatically reducing the ventilatory assistance and indicating the optimal time to perform extubation.
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Maximal expiratory flow in chronic obstructive pulmonary disease (COPD) could be reduced by three different mechanisms; loss of lung elastic recoil, decreased airway conductance upstream of flow-limiting segments; and increased collapsibility of airways. We hypothesized that decreased upstream conductance would be related to inflammation and thickening of the airway walls, increased collapsibility would be related to decreased airway cartilage volume, and decreased collapsibility to inflammation and thickening of the airway walls. Lung tissue was obtained from 72 patients with different degrees of COPD, who were operated upon for a solitary peripheral lung lesion. ⋯ The upstream conductance decreased as the inner wall became thicker. Airway collapsibility did not correlate with the amount of airway cartilage, inflammation, or airway wall thickness. We conclude that the maximal flow-static recoil model does not adequately reflect the collapsibility of the flow-limiting segment.
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In this study we aimed to assess whether the association between asthma (defined by symptoms and bronchial responsiveness) and total immunoglobulin E (IgE) levels was independent of specific IgE levels to common aeroallergens. A general population-based sample, supplemented with symptomatic individuals, comprising 1,916 young adults, aged 20-44 years, from five areas of Spain, performed a face-to-face respiratory questionnaire, and spirometry, and had total and specific serum IgE levels to mites, pets and moulds recorded. In 1,626 of the subjects, a dose-response methacholine challenge test was completed. ⋯ The association between total IgE and asthma also occurred among those with negative specific IgE antibodies (OR 18.0; 95% CI 13.9-120). Individuals with current wheezing and bronchial responsiveness without attacks of asthma also showed an adjusted association with total IgE (OR 4.96; 95% CI 2.32-10.6), which remained for persons without specific IgE (OR 5.86; 95% CI 2.18-1.7). These findings reinforce previous evidence that asthma is associated with increased levels of total IgE, even in subjects negative for specific IgE to common aeroallergens.
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The aim of this study was to determine whether gastric intramucosal pH (pHim) and/or gastric intramucosal carbon dioxide tension (PCO2,im) measured by tonometry can be used to predict the success of weaning in chronic obstructive pulmonary disease (COPD) patients. Twenty six consecutive COPD patients, undergoing mechanical ventilation for acute respiratory failure and satisfying the criteria of weaning from mechanical ventilation with nasogastric tonometer in place, were studied. Arterial blood gas values and PCO2,im were measured 24 h before (H-24), just before (H0), and after 20 min of a weaning trial on T-piece (H20min). ⋯ PCO2,im values during mechanical ventilation are significantly different (p < 0.001) between patients who were successfully weaned and those who were not (6.9 +/- 0.9 vs 9.9 +/- 1.1 kPa (51.9 +/- 6.7 vs 74.3 +/- 8.0 mmHg, respectively)). At H20min, pHim and PCO2,im were still statistically different between the weaning failure and the weaning success group. We conclude that measurement of gastric intramucosal pH (or gastric intramucosal carbon dioxide tension) represents a simple and accurate index to predict weaning outcome in chronic obstructive pulmonary disease patients before attempting weaning.
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In patients with malignancies, thrombocytosis has previously been related to disease stage, histological type, and survival. In the present study, the prevalence of thrombocytosis and the prognostic information provided by platelet counts were analysed in a large cohort of patients with primary lung cancer. At the time of diagnosis, pretreatment platelet counts were retrospectively recorded in 1,115 consecutive patients with histologically proven primary lung cancer. ⋯ Thrombocytosis was not associated with an increased incidence of thromboembolism. In conclusion, thrombocytosis is an independent prognostic factor of survival in patients with primary lung cancer. We suggest that platelet counts should be included in future multivariate analyses of survival in patients with lung cancer.