Peak Flow Meter Characteristics and Asthma.

Abstract

Asthma is an episodic disease characterized by acute airway narrowing in at least two common scenarios. The first is when an irritant such as cigarette smoke, fumes from an industrial source, strong perfume, or even exercise cause an acute bronchospastic event. This type of asthma usually reverses with bronchodilator therapy in the first 2 hours with little subsequent airway inflammation and recovery of peak flows back to the normal range. The only other treatment may be avoidance of the irritant if possible. In a second type of clinical situation, an asthmatic develops ongoing airway inflammation due to daily pollen exposure, chronic cockroach exposure in the household, or other chronic condition causing airway irritation resulting in progressive inflammation and eventual bronchospasm poorly relieved by bronchodilators alone. These patients do not normalize peak flow immediately and require systemic steroids either as an inpatient or outpatient. Normalization of peak flow may occur in 3-4 days or may take up to several weeks of systemic steroids. In both cases, monitoring of airway caliber is done with a peak flow meter.