Sette L, Del Col G, Comis A, Milic-Emili J, Rossi A, Boner A L
Pediatric Dept, University of Verona, Italy.
Eur Respir J. 1996 Sep;9(9):1902-6. doi: 10.1183/09031936.96.09091902.
In adults, both peak expiratory flow (PEF) and forced expiratory volume in one second (FEV1) are significantly influenced by the time course of the inspiration preceding the forced expiration. The aim of this study was to evaluate the effects of three different inspiratory manoeuvres on PEF, FEV1, and forced vital capacity (FVC) in asthmatic children. Twenty five symptomless asthmatic children performed forced expiration preceded by three different inspiratory manoeuvres, which consisted of: a rapid inspiration with a 2 s end-inspiratory breathhold (Manoeuvre No. 1); a rapid inspiration without an end-inspiratory breathhold (Manoeuvre No. 2); and a slow inspiration lasting about 5 s with an end-inspiratory breathhold of at least 4 s (Manoeuvre No. 3). All manoeuvres were performed in a randomly assigned sequence each morning for three consecutive days. In each session, the manoeuvres were repeated three times and the highest value was chosen. Both FVC and FEV1 obtained with Manoeuvre No. 3 were significantly lower than the corresponding values obtained with Manoeuvre Nos. 1 and 2. The mean (SD) FVC values were 2.76 (0.66) L with Manoeuvre No. 1, 2.67 (0.58) L with Manoeuvre No. 2 and 2.52 (0.52) L with Manoeuvre No. 3. The corresponding values of FEV1 were 2.25 (0.53), 2.22 (0.53) and 2.07 (0.44) L, respectively. By contrast, the values of PEF, obtained with a portable peak flow meter, were similar with the three different inspiratory manoeuvres. The results of this study show that in symptomless asthmatic children the preceding inspiratory manoeuvre may influence forced vital capacity and forced expiratory volume in one second. Hence, in order to reduce variability due to interference by physiological factors and so improve reproducibility of pulmonary function tests, the inspiratory manoeuvres must be accurately standardized.
在成年人中，呼气峰值流速（PEF）和一秒用力呼气容积（FEV1）均受到用力呼气前吸气时间过程的显著影响。本研究的目的是评估三种不同吸气动作对哮喘儿童的PEF、FEV1和用力肺活量（FVC）的影响。25名无症状哮喘儿童在进行三种不同吸气动作后进行用力呼气，这三种吸气动作分别为：快速吸气并在吸气末屏气2秒（动作1）；快速吸气但不进行吸气末屏气（动作2）；缓慢吸气持续约5秒并在吸气末屏气至少4秒（动作3）。所有动作在每天早晨以随机分配的顺序连续进行三天。在每个时段，每个动作重复三次并选取最高值。动作3所获得的FVC和FEV1均显著低于动作1和动作2所获得的相应值。动作1的FVC平均（标准差）值为2.76（0.66）升，动作2为2.67（0.58）升，动作3为2.52（0.52）升。FEV1的相应值分别为2.25（0.53）、2.22（0.53）和2.07（0.44）升。相比之下，使用便携式峰值流量计获得的PEF值在三种不同吸气动作下相似。本研究结果表明，在无症状哮喘儿童中，之前的吸气动作可能会影响用力肺活量和一秒用力呼气容积。因此，为了减少生理因素干扰导致的变异性并提高肺功能测试的可重复性，吸气动作必须进行准确的标准化。
