Mandros Charalampos, Tsiakalos Aris, Tzelepis George E
Department of Pathophysiology, University of Athens Medical School, Greece.
Respir Med. 2007 May;101(5):933-7. doi: 10.1016/j.rmed.2006.09.014. Epub 2006 Oct 16.
In adults performing forceful expiratory maneuvers, the length of post-inspiratory pause prior to forced expiration may influence the subsequently measured peak expiratory flow (PEF) and increase its variability. We investigated the effects of two different lengths of breath-hold at total lung capacity (TLC) on the short-term reproducibility of PEF in healthy volunteers.
Forty-six healthy volunteers (age 34.6+/-8.5; 23 men) performed a series of maximal forceful expirations in two different test sessions, separated by approximately 2 weeks. In each test-session, PEF was measured with two different types of maneuvers. One maneuver (P) included a brief (<2s) post-inspiratory pause at TLC prior to forced expiration, whereas the second maneuver (NP) included no pause at TLC. The speed of inspiration to TLC was fast and similar for both maneuvers. In a given test session, all volunteers performed four efforts for each type of maneuver. The highest PEF for each maneuver was used for analysis. The Bland-Altman statistical analysis was used to determine inter-session reproducibility of PEF.
Within-maneuver analysis of the between-test session reproducibility of PEF showed that neither maneuver systematically biased the measured PEF (mean difference 0.02L/s for the P and 0.17L/s for the NP maneuver). Inter-maneuver between-test session analysis similarly showed that neither maneuver introduced a systematic bias in the maximal PEF (mean difference ranged from -0.15 to -0.01L/s). The limits of agreement were comparable in all maneuver-pair analyses.
Forceful expiratory maneuvers with or without a brief (<2s) pause at TLC produce comparable PEF values in test-retest sessions.
在进行用力呼气动作的成年人中，用力呼气前吸气后暂停的时长可能会影响随后测得的呼气峰值流速（PEF）并增加其变异性。我们研究了在总肺容量（TLC）下两种不同屏气时长对健康志愿者PEF短期重复性的影响。
46名健康志愿者（年龄34.6±8.5岁；23名男性）在两个不同的测试环节中进行了一系列最大用力呼气动作，两个环节间隔约2周。在每个测试环节中，用两种不同类型的动作测量PEF。一种动作（P）包括在用力呼气前于TLC处进行短暂（<2秒）的吸气后暂停，而第二种动作（NP）在TLC处不进行暂停。两种动作吸气至TLC的速度都很快且相似。在给定的测试环节中，所有志愿者对每种动作类型都进行了四次努力。每种动作的最高PEF用于分析。采用Bland-Altman统计分析来确定PEF的测试环节间重复性。
对PEF测试环节间重复性的动作内分析表明，两种动作均未系统性地使测得的PEF产生偏差（P动作的平均差异为0.02L/s，NP动作的平均差异为0.17L/s）。动作间测试环节间分析同样表明，两种动作均未在最大PEF中引入系统性偏差（平均差异范围为-0.15至-0.01L/s）。在所有动作对分析中，一致性界限相当。
在TLC处有或没有短暂（<2秒）暂停的用力呼气动作在重测环节中产生的PEF值相当。
