The European respiratory journal : official journal of the European Society for Clinical Respiratory Physiology
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Randomized Controlled Trial Clinical Trial
Tiotropium bromide, a new long-acting antimuscarinic bronchodilator: a pharmacodynamic study in patients with chronic obstructive pulmonary disease (COPD). Dutch Study Group.
The objective of the present study was to investigate the dose-dependent bronchodilator efficacy and duration of action of the newly developed antimuscarinic agent tiotropium bromide in patients with chronic obstructive pulmonary disease (COPD). In a randomized, double-blind, placebo-controlled, crossover design, patients inhaled single doses of 10-80 micrograms tiotropium bromide and placebo, formulated in lactose powder capsules. The washout period between test doses was 72 h. ⋯ After excluding carry-over effect, the peak response to placebo decreased to 11%, whilst for tiotropium bromide doses it ranged 20-25%; standard error for mean difference was about 4%. There was no evidence of systemic anticholinergic effects. In this population of patients with COPD, tiotropium bromide was found to be a safe and long-acting bronchodilator, demonstrating a clear dose-response relationship following single dose administration.
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Potential risk factors for developing Haemophilus influenzae nosocomial pneumonia have not been sufficiently studied. We wanted to investigate the incidence and risk factors for the development of Haemophilus influenzae pneumonia in the hospital by means of a multivariate analysis. A total of 468 cases of nosocomial pneumonia were observed during the study period, 317 (68%) of which were aetiologically diagnosed by means of highly reliable methods, and H. influenzae was isolated in 57 of them. ⋯ In nonintubated patients, no risk factors were found for H. influenzae pneumonia compared with other nosocomial pneumonia. We conclude that H. influenzae was involved in 57 out of 317 (18%) of nosocomial pneumonia registered in our institution, and the majority of patients (50 out of 57) were mechanically-ventilated. In this particular subgroup, coma of the patient on admission to hospital and absence of antibiotic treatment prior to developing pneumonia constitute two definite risk factors for developing H. influenzae nosocomial pneumonia.
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Diaphragm strength can be assessed by measurement of transdiaphragmatic pressure (Pdi) in response to stimulation of the phrenic nerves. The length-tension relationship of the diaphragm can be studied by measuring twitch Pdi over the range of lung volume. Previous studies of the relationship between lung volume and diaphragm strength have used the technique of electrical stimulation of the phrenic nerves. ⋯ In relative terms, the effect of potentiation became greater as lung volume increased, and more than doubled twitch Pdi at TLC. With increasing lung volume, there is a linear fall in unpotentiated twitch Pdi with a slope that is less steep, over the same range of absolute lung volume, than previously reported. When assessing diaphragm strength by the twitch technique, it is essential to control for lung volume and equally important to control for twitch potentiation.