Reversible airway obstruction is defined as ___ percentage increase in FEV1, 15 minutes after an inhaled sho-acting beta 2 -agonist therapy-
High-Yield Explanation
Diagnosis of reversible airway obstruction or asthma is made when FEV1 >/= 15% (and 200 ml) increase following administration of a bronchodilator ,like sho acting beta2 agonists, or trial of coicosteroids.It can also be diagnosed as >20% diurnal variation on >/= 3 days in a week for 2 weeks on PEF diary & FEV1 >/= 15% decrease after 6 mins of exercise. Reference:Davidson's medicine-22nd edition,page no:668/