Consistency of repeated flow-volume parameters in airway challenge studies.
A maximal lung inflation is known to alter airway tone in man. Recent investigations, examining how this phenomenon relates to bronchial provocation testing, suggest that a deep inspiration will decrease airway resistance and underestimate the subsequent decrement in lung function following airway challenge. Because the recovery of baseline tone is rapid following a deep inspiration, we evaluated the consistency of three consecutive partial and maximal expiratory flow-volume maneuvers performed at approximately 45- to 60-second intervals. Functional parameters including the forced expiratory volume in 1 s and the maximal expiratory flow at 60% of the vital capacity below total lung capacity on the partial curve (MEF40%P) were constant at each measurement point following induced bronchoconstriction or bronchodilation in both healthy and asthmatic subjects. We suggest that with 45 s between maneuvers, repeatable parameters can be attained from three consecutive flow-volume curves.
Witek
T J
TJ
Department of Medicine, Mt. Sinai Medical Center, New York, N.Y.
Stark
E
E
Schachter
E N
EN
D000403:Airway Resistance; D001249:Asthma / Q000503:physiopathology; D001985:Bronchial Provocation Tests; D006801:Humans; D008168:Lung / Q000502:physiology*; D008176:Lung Volume Measurements; D012123:Pulmonary Ventilation; D012119:Respiration