In an asthmatic patient which of the following pulmonary functions would show the greater improvement on inhaling a bronchodilator
High-Yield Explanation
In an asthmatic patient,simple spirometry confirms airflow limitation with a reduced FEV1,FEV1/FVC ratio,and PEF(peak ejection fraction).Reversibility is demonstrated by a>12% and (200 ml) increase in FEV1 15 minutes after an inhaled sho acting beta2 agonist(bronchodilator).In some patients,similar response is obtained by a 2 to 4 week trial of oral coicisteroids(prednisolone30-40 mg daily). Reference;:Harrison's Medicine,18the edition,page no:2109.