Assessment of reproducibility of exhaled hydrogen peroxide concentration and the effect of breathing pattern in healthy subjects.

Background: Hydrogen peroxide (H2O2) is detectable in exhaled breath condensate (EBC) and has been proposed to be a surrogate marker of oxidative stress in the airways. In this study we tested whether the breathing pattern during EBC collection influences the concentration of exhaled H2O2.

Methods: EBC was collected during (1) tidal breathing and (2) breathing with increased tidal volume for 10 min from 16 healthy volunteers.

Exercise increases exhaled breath condensate cysteinyl leukotriene concentration in asthmatic patients.

Background: Although the importance of cysteinyl leukotrienes (Cys-LTs) in exercise-induced bronchoconstriction (EIB) is supported by various sources of evidence, how the concentration of these mediators change during the development of EIB has not been investigated.

Objectives: Our goal was to determine the effect of exercise on the concentration of airway Cys-LT in asthmatic patients by measuring Cys-LT in exhaled breath condensate (EBC).

Methods: Seventeen atopic asthmatic patients with a previous history of EIB and six healthy volunteers were studied.

Exhaled breath condensate detects markers of pulmonary inflammation after cardiothoracic surgery.

Cardiac surgery using cardiopulmonary by-pass and, to a greater extent, lung resection, causes acute lung injury that is usually subclinical. Analysis of mediators in exhaled breath condensate is a promising means of monitoring inflammation in a variety of airway diseases but the contribution of the airway lining fluid from the lower respiratory tract is uncertain. We compared the analysis of markers of lung injury in exhaled breath condensate and bronchoalveolar lavage in endotracheally intubated patients before and after coronary artery bypass graft surgery with cardiopulmonary bypass and lobectomy.