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Spirometry has been strongly recommended in cases where diagnosis of asthma is being considered as most physicians are not good at diagnosing if obstruction of airways is reversible or not. The following findings are important indicators of reversibility of broncho-constriction in a case of asthma. 1) Peak Flow variation by more than 20% from pre inhaler PF in AM compared to PF post inhaler in mid afternoon 2) After bronchodilator, FEV 1 increases either by more than 200cc or by more than 12% of pre-bronchodilator value. Spirometry is better for diagnosing because peak flow varies from manufacturer to manufacturer. Spirometry can be considered after age 4 (some kids at 7). It is critical for the exam to know when you must start a preventive therapy like inhaled steroids: Preventive therapy should be initated if symptoms occur more than twice a WEEK in the daytime or more than twice a MONTH at night-time. Another critereon is usage of more than 2 inhaler canisters in a year. At this stage - asthma is considered persistent as opposed to intermettent. Other preventive measures include LtD4 inhibitors, Salmeterol and Theophylline. In non responders, oral steroids can be used. |