Exhaled carbon monoxide levels in school‐age children with episodic asthma

Abstract

Carbon monoxide (CO) can be detected in exhaled air and is increased in adult and childhood persistent asthmatic patients. However, little is known about the exhaled CO concentration in episodic childhood asthma. This study aimed to clarify whether measurement of exhaled CO is useful in monitoring disease activity in children with episodic asthma. We measured exhaled CO concentration by modified Micro-Smokerlyzer in 217 elementary school children (132 boys; mean age, 10 +/- 1 (SE) years; range, 9-12 years), in whom 29 had infrequent episodic asthma without current exacerbations. We also measured exhaled CO concentrations in 22 children with episodic asthma (13 boys; mean age, 10 +/- 3 years; range, 8-12 years), who had acute mild asthmatic attacks during examination. In these patients with mild asthmatic attacks, exhaled CO was measured both before and after combination therapy with salbutamol and sodium cromoglycate (SCG) by powered nebulizer. Among 217 schoolchildren, exhaled CO levels in infrequent episodic asthmatic children (1.1 +/- 0.1 parts per million (ppm), n = 29) were not significantly different from those in healthy schoolchildren (1.0 +/- 0.1 ppm, n = 188, P > 0.68). The exhaled CO concentrations during asthma attacks in children with episodic asthma were significantly higher (5.1 +/- 0.4 ppm, n = 22) compared with those in healthy children (P < 0.001) or those in asymptomatic asthmatic children (P < 0.001). The elevated exhaled CO levels were significantly decreased after inhalation therapy of a combination of salbutamol and SCG (3.2 +/- 0.5 ppm, n = 22, P < 0.02). In conclusion, exhaled CO levels were significantly elevated during acute asthma exacerbations, and partially recovered after treatment with beta(2)-agonist and SCG in children with mild episodic asthma. These findings indicate that measurement of exhaled CO might provide another noninvasive measurement of asthma exacerbations that would be suitable for use in children with acute mild episodic asthma.

Alterations of the tear film and ocular surface health in chronic smokers

“…Blood carboxyhemoglobin concentrations were also displayed by the device and recorded in each case. 31 …”

Factors influencing the levels of exhaled carbon monoxide in asthmatic children

“…Another similar study with 20 participants demonstrated a significant increase in eCO during asthma exacerbation [27]. Ohara et al [6] found that eCO levels in infrequent episodic asthmatic children were not different from those in healthy schoolchildren, but increased significantly during asthma attacks. Several authors have suggested that the elevation of eCO amounts could be related to the severity or clinical control of bronchial asthma.…”

“…Many studies have confirmed that the analysis of exhaled breath can be used for disease monitoring and the modification of the applied therapy. Besides the commonly used FE NO measurement, several authors have suggested that exhaled carbon monoxide (eCO) can also be used in bronchial asthma [5][6][7][8][9] and in several other respiratory diseases such as allergic rhinitis (AR) [10], chronic pulmonary obstructive disease [11], bronchiectasis [12], cystic fibrosis [13], primary ciliary dyskinesia [12] or acute respiratory infections [10,14]. The eCO was studied also as a potential marker for evaluation of lifestyles and stress levels [15].…”

The Role of Heme Oxygenase-1 in T Cell-Mediated Immunity: The All Encompassing Enzyme

“…Patients with asthma have an increased level of exhaled CO, which is likely due to the result of up-regulated HO-1 activity [108][109][110]. Lim found that HO-1 is widely distributed under the mucosa of the airway, especially in the endothelial cells and CD68 + macrophages under certain environmental influences [111].…”