Clinical analysis of asthma patients with wheezing despite normal ventilatory function

Choi, Inseon S; Lim, Ho; Koh, Youngil I; Chung, Se Woong

Abstract

BACKGROUND
Wheezing is one of the characteristics of asthma, Intensity of wheezing is correlated with the severity of airway obstruction. However, some asthmatic patients may show wheezing despite normal ventilatory function.
OBJECTIVE
To determine the cause of wheezing in asthmatic patients with normal ventilatory function. METHODS: Thirty-eight consecutive asthmatic patients with wheezing despite FEV1> or =80% of predicted value were retrospectively examined for clinical data. RESULTS: Twenty-seven patients (71.1%) were women. Sixteen patients (42.1%) showed airway obstruction based on the Intermountain Thoracic Society criteria. Patients with airway obstruction had significantly lower FEF50% than did those without it (P<.001). When the patients with no wheezing were re-examined by the pulmonary function test. 14 patients (48.3%) showed a significant bronchodilation. In patients without airway obstruction, FEF50/FIF50 was significantly higher than in those with it (P<.01), and FEF50/FIF50 >1 suggesting upper airway obstruction was observed in 7 of 16 (43.8%) patients. Associated diseases were rhinitis in 21 (55.3%) patients, sinusitis in 18 (47.4%), and postnasal drip syndrome in 3 (7.9%). CONCLUSIONS: Wheezing despite normal ventilatory function in asthma occurs more often in women. It may be related to reversible airway obstruction in nearly half patients and to upper airway obstruction such as rhinitis. in considerable numbers of the remaining patients.