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LABA/ICS combination reduces parasternal muscle activity in COPD
(parasternal muscle activity 这意思不是很清楚）
MedWire News: Treatment with a combined long-acting beta agonist (LABA) and inhaled corticosteriod (ICS) reduces chest wall parasternal inspiratory muscle activity in chronic obstructive pulmonary disease (COPD) patients and may help alleviate dyspnea, say researchers.
Writing in the journal Chest, Paul Easton, (University of Calgary, Alberta, Canada) and team explain: “As COPD hyperinflation worsens, diaphragm efficiency decreases, and a compensatory increase in chest wall inspiratory muscle activity occurs.”
To investigate whether treatment with a LABA/ICS combination of salmeterol/fluticasone (SFC) can help decrease parasternal inspiratory muscle activity in COPD patients, the team studied 12 patients, aged 50–74 years, with severe Global Initiative on Obstructive Lung Disease stage III-IV disease who had a mean FEV1 of 0.91 l and 32% of the predicted value.
The participants were asked to take four puffs of salmeterol 25 µg and fluticasone propionate 125 µg via a metered dose combination inhaler. Electromyogram readings from electrodes placed on the patients’ chests were taken before and after treatment to record parasternal inspiratory muscle activity.
The participants also underwent extensive pulmonary function tests before and after receiving salmeterol/fluticasone combination treatment.
The researchers found that in all the patients, parasternal inspiratory muscle activity was significantly and greatly reduced 1 and 2 hours after SFC treatment compared with beforehand.
These reductions corresponded with significant improvements in ventilation and breathing patterns.
However, FEV1 improved by a mean of just 4.2% and forced vital capacity by a mean of just 5.2% after SFC treatment compared with beforehand. These improvements were not significant and indicated that SFC treatment did not result in bronchodilation in this group of patients.
This, say the researchers, is probably due to the severe nature of COPD in the study patients.
Easton and team conclude: “In severe COPD, with minimal change in hyperinflation or pulmonary mechanics, salmeterol/fluticasone induced a significant decrease in activity of the chest wall parasternal inspiratory muscle.”
They add: “This may be of practical benefit to reverse the extensive use of the chest wall muscles and alleviate dyspnea in severe COPD.”
MedWire (www.medwire-news.md) is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010 |
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发表于 2010-3-14 09:22:15