The effect of inhaled nitric oxide and helium-oxygen mixture on the airway of healthy man

Objective: To evaluate the effect of inhaled nitric oxide （NO） and Helium Oxygen mixture （Heliox） on the airway of healthy bronchoprovocation man.Methods: 12 healthy non smoking men were included in this research The bronchoconstriction of the subject was induced by inhaled methacholine The man sat and breathed with a nasal mask through a mechanical ventilator The research course was divided into the following three steps Inhalation of air after bronchoconstriction; inhalation of Heliox; and inhalation of NO and Heliox The FVC, FEV 1 and MMF were monitored during the research.Results: After bronchoprovocation challenged, FEV 1 and MMF decreased significantly Comparing with the inhalation of air, FEV 1 and MMF increased during the inhalation of Heliox FEV 1 can be increased more when NO was put in Heliox But MMF was not changed FVC was only increased slightly during the inhalation of Heliox or the inhalaton of Heliox and NO simultaneously.Conclusion: The study suggested that the high dose of NO can resist the brochoconstriction, but the effect was insufficient The effect of Heliox on airway is stronger than NO, because Heliox can influence either the large airway or the small airway