Pijnenburg M W H, Lissenberg E T, Hofhuis W, Ghiro L, Ho W C J, Holland W P, de Jongste J C
Dept of Paediatrics/Respiratory Medicine, Erasmus MC University Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands.
Eur Respir J. 2002 Oct;20(4):919-24. doi: 10.1183/09031936.02.01282002.
Fractional exhaled nitric oxide concentration (FENO) depends on exhalation flow; however, children often are unable to perform controlled flow procedures. Therefore, a device was developed for off-line FENO sampling, with dynamic flow restriction (DFR). The authors compared off-line with on-line FENO, assessed feasibility, and obtained normal values for FENO in children aged 4-8 yrs. Subjects inhaled nitric oxide (NO)-free air and exhaled into the device, where DFR kept exhalation flow constant at 50 mL x s(-1). Dead space air was discarded. Exhaled air was collected in a 150 mL mylar balloon. On-line measurements were performed and values compared with off-line FENO in 19 adult volunteers. Seventy-nine children performed off-line sampling. All samples were analysed with a chemiluminescence NO-analyser. Normal values were obtained in 34 healthy children. There was an excellent correlation between on- and off-line values. Bland and Altman plots showed good agreement between on- and off-line FENO. Seventy-four out of 79 children were able to perform a correct off-line procedure. Geometric mean+/-SEM FENO in healthy children was 4.9+/-1.2 parts per billion (ppb) for male children and 7.6+/-1.1 ppb for female children. It can be concluded that off-line fraction of exhaled nitric oxide measurements with dynamic flow restriction are feasible in young children and correspond to on-line values.
呼出一氧化氮分数浓度（FENO）取决于呼气流量；然而，儿童往往无法进行控制流量的操作。因此，开发了一种用于离线FENO采样的设备，具有动态流量限制（DFR）。作者比较了离线和在线FENO，评估了可行性，并获得了4 - 8岁儿童FENO的正常值。受试者吸入无一氧化氮（NO）的空气并呼气到该设备中，DFR使呼气流量保持恒定在50 mL×s⁻¹。死腔空气被丢弃。呼出的空气收集在一个150 mL的聚酯薄膜气球中。对19名成年志愿者进行了在线测量，并将测量值与离线FENO进行比较。79名儿童进行了离线采样。所有样本均用化学发光NO分析仪进行分析。在34名健康儿童中获得了正常值。在线和离线值之间存在极好的相关性。Bland和Altman图显示在线和离线FENO之间具有良好的一致性。79名儿童中有74名能够正确进行离线操作。健康儿童的几何平均值±标准误，男性儿童的FENO为4.9±1.2十亿分之一（ppb），女性儿童为7.6±1.1 ppb。可以得出结论，具有动态流量限制的离线呼出一氧化氮测量在幼儿中是可行的，并且与在线值相符。
