A method to study the effect of bronchodilators on smoke retention in COPD patients: study protocol for a randomized controlled trial.

Abstract:

BACKGROUND:Chronic obstructive pulmonary disease (COPD) is a common disease, associated with cardiovascular disease. Many patients use (long-acting) bronchodilators, whilst they continue smoking alongside. We hypothesised an interaction between bronchodilators and smoking that enhances smoke exposure, and hence cardiovascular disease. In this paper, we report our study protocol that explores the fundamental interaction, i.e. smoke retention. METHOD:The design consists of a double-blinded, placebo-controlled, randomised crossover trial, in which 40 COPD patients smoke cigarettes during both undilated and maximal bronchodilated conditions. Our primary outcome is the retention of cigarette smoke, expressed as tar and nicotine weight. The inhaled tar weights are calculated from the correlated extracted nicotine weights in cigarette filters, whereas the exhaled weights are collected on Cambridge filters. We established the inhaled weight calculations by a pilot study, that included paired measurements from several smoking regimes. Our study protocol is approved by the local accredited medical review ethics committee. DISCUSSION:Our study is currently in progress. The pilot study revealed valid equations for inhaled tar and nicotine, with an R2 of 0.82 and 0.74 (p < 0.01), respectively. We developed a method to study pulmonary smoke retentions in COPD patients under the influence of bronchodilation which may affect smoking-related disease. This trial will provide fundamental knowledge about the (cardiovascular) safety of bronchodilators in patients with COPD who persist in their habit of cigarette smoking. TRIAL REGISTRATION:ClinicalTrials.gov: NCT00981851.

journal_name

Trials

journal_title

Trials

authors

van Dijk WD,Scheepers PT,Cremers R,Lenders JW,Klerx W,van Weel C,Schermer TR,Heijdra Y

doi

10.1186/1745-6215-12-37

subject

Has Abstract

pub_date

2011-02-10 00:00:00

pages

37

issn

1745-6215

pii

1745-6215-12-37

journal_volume

12

pub_type

杂志文章,随机对照试验

相关文献

Trials文献大全