Respiratory medicine
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Respiratory medicine · Mar 2010
Breath-by-breath quantification of progressive airflow limitation during exercise in COPD: a new method.
During heavy exercise in chronic obstructive pulmonary disease (COPD), dynamic airways compression leads to a progressive fall in intrabreath flow. This is manifested by concavity in the spontaneous expiratory flow-volume (SEFV) curve. We developed a method to quantify the SEFV curve configuration breath-by-breath during incremental exercise utilizing a computerized analysis. ⋯ SEFV in healthy individuals manifested progressively more convex SEFV curves throughout exercise (RAR=0.56+/-0.08 at rest and 0.61+/-0.05 at peak exercise), but became progressively more concave in COPD patients (RAR=0.52+/-0.08 at rest and 0.46+/-0.06 at peak exercise). In conclusion, breath-by-breath quantification of SEFV curve concavity describes progressive shape changes denoting expiratory flow limitation during incremental exercise in COPD patients. Further studies are warranted to establish whether this novel method can be a reliable indicator of expiratory flow limitation during exercise and to examine the relationship of RAR time course to the development of dynamic hyperinflation.
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Respiratory medicine · Mar 2010
Serial interferon-gamma release assays after rifampicin prophylaxis in a tuberculosis outbreak.
Even though some studies have reported the results of serial interferon-gamma release assays (IGRAs) during isoniazid prophylactic treatment, serial results have not been reported after rifampicin prophylaxis. A contact investigation was conducted after a tuberculosis (TB) outbreak in an accommodation facility. The tuberculin skin test (TST) and the QuantiFERON-TB Gold In-Tube (QFT-GIT) test were performed in 214 contacts with normal chest radiographs. ⋯ Subjects without QFT-GIT test reversion had a significantly higher baseline TST induration sizes (18.3+/-4.8 vs. 14.9+/-3.4mm, p<0.01) and IFN-gamma levels (18.6+/-17.9 vs. 3.2+/-7.5IU/mL, p<0.01) than the subjects with QFT-GIT test reversion. Thus, IGRAs may be useful in evaluating the therapeutic response to rifampicin prophylaxis in TB contacts. However, considering that this was not a controlled study, a prospective controlled study is needed to determine whether rifampicin prophylaxis truly affects QFT-GIT reversion.
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Respiratory medicine · Mar 2010
Effect of mannitol and repetitive coughing on the sputum properties in bronchiectasis.
Mucociliary clearance increases with increasing doses of mannitol and clearance is enhanced when mannitol inhalation is followed by repetitive voluntary coughing. The aim of the study was to investigate: 1) the effect of increasing doses of mannitol and repetitive coughing on the sputum physical properties; 2) if the changes in sputum properties can predict the efficacy of mucus clearance measured by radioaerosol technique in bronchiectasis patients. Sputum was collected from 14 patients, age: 63+/-6yr, who participated on the mucociliary and cough clearance studies at baseline, with mannitol (160, 320 and 480mg) and control (Daviskas et al. ERJ 2008; 31:765-772). Sputum was collected: 1) on the screening visit before and after mannitol challenge (635mg); 2) at the start and end of each clearance study after 100 repetitive voluntary coughs except on the control study (no mannitol or repetitive coughing). The sputum solids content, surface tension, contact angle and rheology were measured. Mannitol in association with coughing and coughing alone reduced the solids content, surface tension, contact angle and viscoelastic sputum properties (p<0.0001) and this effect, unlike mucociliary clearance, was not dose dependent. The control produced no effect. Total mucus clearance correlated only with the percentage reduction in surface tension on 480mg mannitol and with the reduction in solids content at baseline. ⋯ Inhaled mannitol and voluntary repetitive coughing improved the sputum physical properties in bronchiectasis patients and this effect was not dose dependent. Changes in sputum properties do not predict efficacy of mucociliary and cough clearance.
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Respiratory medicine · Feb 2010
Randomized Controlled Trial Multicenter Study Comparative StudyTiotropium 5microg via Respimat and 18microg via HandiHaler; efficacy and safety in Japanese COPD patients.
To compare the efficacy and safety of tiotropium inhaled via Respimat Soft Mist Inhaler, a multidose propellant-free inhaler and HandiHaler, a single-dose dry powder inhaler, in a phase 2 study of Japanese COPD patients. ⋯ In Japanese patients with COPD, tiotropium Respimat 5microg and tiotropium HandiHaler 18microg showed a similar profile of efficacy, safety and pharmacokinetics.
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Respiratory medicine · Feb 2010
Randomized Controlled Trial Multicenter StudyAdditive effects of transdermal tulobuterol to inhaled tiotropium in patients with COPD.
The current mainstream treatment for COPD is bronchodilators alone or in combination. The effects of a beta(2)-agonist, tulobuterol, administered transdermally, have been reported to last for 24h. However, there are no reports on the efficacy of tulobuterol combined with an anticholinergic. In this study, we investigated the efficacy and safety of transdermal tulobuterol combined with inhaled tiotropium in COPD. ⋯ In COPD patients, additional administration of transdermal tulobuterol to inhaled tiotropium produced significant benefits in dyspnea and SGRQ score as well as pulmonary function. These benefits may be due to a reduction in pulmonary hyperinflation resulting from improvement of peripheral airflow obstruction through tulobuterol via the systemic circulation.