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

INTRODUCTION: The benefits of β-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. METHODS: EBC was collected before and 30 minutes after administration of inhaled salbutamol (800 μg). 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 B(4 )concentration was measured after sample lyophilization and reconstitution. Results are expressed as the median (interquartile range). RESULTS: 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 PaO(2)/F(I)O(2 )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) μM versus 21.21 (8.07 to 29.83) μM, 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 B(4 )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). CONCLUSION: 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.