Breathing pattern and chest wall kinematics during phonation in chronic obstructive pulmonary disease patients.

BACKGROUND Breathing pattern description and chest wall kinematics during phonation have not been studied in male and female patients with chronic obstructive pulmonary disease. OBJECTIVES We used optoelectronic plethysmography to provide a quantitative description of breathing pattern and chest wall kinematics. METHODS Volumes of chest wall compartments (rib cage and abdomen) were assessed in 15 patients while reading aloud (R), singing (SI) and during high-effort whispering (HW). RESULTS Relative to quiet breathing, tidal volume and expiratory time increased while inspiratory time decreased. The expiratory flow decreased during R and SI, but was unchanged during HW. In males, the end-expiratory volume decreased as a result of a decreased volume of rib cage during R, SI and HW and due to a decreased volume of abdomen during HW. In females, a decrease in end-expiratory volume was accomplished by a decrease in abdominal volume during R and HW. During R, the chest wall end-expiratory volume of the last expiration in females was to the left of the maximal expiratory flow volume curve (MEFV), with still substantial expiratory reserve volume available. In contrast, during SI and HW in females and during all types of phonation in males, chest wall end-expiratory volume of the last expiration was well to the right of the MEFV curve and associated with respiratory discomfort. Gender had a greater importance than physical characteristics in determining more costal breathing in females than in males under all conditions studied. CONCLUSIONS Phonation imposes more abdominal breathing pattern changes in males and costal changes in females. Expiratory flow encroaches upon the MEFV curve with higher phonatory efforts and respiratory discomfort.