Clinical significance of forced expiratory wheezing in chronic airflow obstruction

Jang, An Soo; Choi, Inseon; Park, Seog Chae; Yang, Joo Yeol

Abstract

BACKGROUND: Wheezing which is defined as a continuous sound with a musical quality is commonly auscultated in patients with chronic obstructive airway diseases. The correlation between wheezing and airway obstruction is unclear.
OBJECTIVE
This study was designed to evaluate the relationships among wheezing, severity of airway obstruction, and pulmonary function tests. METHOD: Forty-one subjects were examined by the same observer. Wheezing during normal breathing and maximal forced exhalation, was auscultated respectively. Posterior lung bases were auscultated bilaterally with the seated patient taking repeated inspiratory capacity breaths through an open mouth. To quantify wheezing intensity, a regional score was assigned for each area after a minimum of 3 breaths, according to the following scale: zero, no wheezing heard: one, faint or intermittent wheezes: two, moderate wheezing during every expiration: three, loud wheezing during every expiration. The lung function tests by standard pneumotachograph were performed by skilled technicians.
RESULTS
Wheezing was auscultated more in forced exhalation than in normal breathing in patients with asthma and COPD [8/9(88%) vs 1/9(11%), p<0.01 ll/15(73%) vs 1/15(6%), p<0.05)]. Forced expiratory wheezes group (n=25) compared to no wheezes group (n=16) had significantly lower FEVl (75+-5.8% vs 95.6+-6.6%, p<0.05). Compared to no wheezes group, the group with forced expiratory wheezes had lower FEV1 and FEV1/FVC (50.4+- 21.3% vs 81.15+-27.7%, 70.4+-22.4% vs 92.5+-19.3%, respectively, p<0.05). Bronchial asthma compared with COPD tended to have higher wheezing scores (Wheeze scores Bronchial asthma 3.5 vs COPD 2.4, p=0.08). Wheezing scores were correlated to FEV1 (normal breathing: r=-0.35, p<0.05: forced exhalation: r=-0.45, p<0.05), but no differences were found in wheezing incidence according to severity of airway obstruction.
CONCLUSION
These findings suggest that wheezing on maximal forced exhalation may be a useful physical indicator for evaluating the severity of airway obstruction.