Effects of salbutamol on exhaled breath condensate biomarkers in acute lung injury: prospective analysis

The benefits of beta-adrenergic stimulation have been described in acute lung injury (ALI), but there is still no evidence of its anti-inflammatory effect in these patients. Biomarkers in exhaled breath condensate (EBC) were used to study the effects of salbutamol on lung inflammation in mechanically ventilated patients with ALI. EBC was collected before and 30 minutes after administration of inhaled salbutamol (800 microg). The following parameters were measured in the samples: volume obtained, conductivity, pH after helium deaeration, and concentration of nitrites, nitrates and 8-isoprostane. The leukotriene B4 concentration was measured after sample lyophilization and reconstitution. Results are expressed as the median (interquartile range). EBC was obtained from six ALI patients, with a median age of 56 (46 to 76) years. At the time of EBC collection, the Lung Injury Score was 3 (2.3 to 3.1) and the PaO2/FIO2 ratio was 133 (96 to 211) mmHg. A significant increase in deaerated EBC pH was observed after salbutamol administration (7.66 (7.58 to 7.75) versus 7.83 (7.67 to 7.91), P = 0.028). Trends toward decreased nitrosative species (18.81 (13.33 to 49.44) microM versus 21.21 (8.07 to 29.83) microM, P = 0.173) and decreased 8-isoprostane concentration (11.64 (7.17 to 17.13) pg/ml versus 6.55 (4.03 to 9.99) pg/ml, P = 0.068) were detected. No changes in leukotriene B4 concentration were found (1.58 (0.47 to 3.57) pg/ml versus 2.06 (1.01 to 3.01) pg/ml, P = 0.753). EBC analysis is a noninvasive technique that can be used to monitor ventilated patients. In EBC from a small cohort of patients with ALI, inhaled salbutamol significantly decreased airspace acidosis, a marker of inflammation, and was associated with a trend toward decreased markers of nitrosative and oxidative stress.