Abstract
Aims: Exhaled carbon-monoxide (eCO) has been implicated as a pulmonary biomarker in various respiratory diseases. The aim of this longitudinal study was to investigate whether serious acute exacerbation of chronic obstructive pulmonary disease (AECOPD) requiring hospitalization is associated with an increase in eCO and to see if recovery is accompanied by a reduction of eCO level.
Methods:Levels of eCO along with routine clinical variables were measured in 29 current smoker and 33 ex-smoker COPD patients at the time of at hospital admission, and also at discharge following regular treatment.
Results:Levels of eCO were increased in current smokers, both during exacerbation (6.0 [2.0-9.5] vs. 1.0 [1.0-2.0] ppm, p<0.001)and after treatment (7.0 [2.0-12.5] vs. 1.0 [1.0-2.0] ppm, p<0.001) compared to ex-smokers. Exacerbation did not affect eCO levels. Investigating a subgroup of current smoker patients (n=15) there was a significant correlation between levels of eCO and blood carboxyhemoglobin (Hb-CO) concentrations (r=0.464, p<0.01). No associations were found between eCO and lung function or blood gas parameters.
Conclusions: Our results suggest that eCO may be involved in smoking-associated inflammatory processes in the airways, but its monitoring during an episode of AECOPD is of limited clinical value.
- © 2014 ERS