Department of Pediatric Respiratory Medicine, Erasmus University Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands.
Pediatr Pulmonol. 2014 Jan;49(1):15-20. doi: 10.1002/ppul.22782. Epub 2013 Feb 8.
International guidelines recommend measuring fractional exhaled nitric oxide (FeNO) during a single slow exhalation with a constant flow of 50 ml/sec. We developed a new algorithm to compute FeNO at 50 ml/sec from tidal breathing measurements. The main objective is to assess the correlation and agreement of this algorithm with the conventional single breath FeNO measurements.
We recruited children aged 6-18 years, who performed both a single breath and a tidal breathing FeNO measurement in random order. Both maneuvers were performed on the Eco Medics NO-analyser (Eco Physics AG, Duernten, Switzerland).
We included 109 patients between January 2011 and April 2011. Geometric mean (95% CI) FeNO values did not differ significantly between single breath and tidal breathing technique: 21.0 (17.7-24.8) ppb and 20.0 (17.0-23.6) ppb (P = 0.18), respectively. We found an excellent intraclass correlation coefficient of 0.96 (0.94-0.97) and moderate agreement with a mean difference of 4% (95% limits of agreement -43% and +90%).
Tidal breathing FeNO values could be transformed with a new algorithm to match single breath FeNO at a constant flow of 50 ml/sec. This algorithm opens the way to standardized FeNO measurements in preschool children and uncooperative patients.
国际指南建议在 50ml/sec 的恒流条件下通过单次缓慢呼气来测量呼出气一氧化氮分数（FeNO）。我们开发了一种新算法，可从潮气呼吸测量值计算出 50ml/sec 时的 FeNO。主要目的是评估该算法与传统单口气 FeNO 测量值的相关性和一致性。
我们招募了年龄在 6-18 岁的儿童，他们随机先后进行了单口气和潮气呼吸 FeNO 测量。两种操作均在 Eco Medics NO 分析仪（Eco Physics AG，Duernten，瑞士）上进行。
我们纳入了 2011 年 1 月至 2011 年 4 月间的 109 名患者。单口气和潮气呼吸技术的几何均数（95%CI）FeNO 值无显著差异：分别为 21.0（17.7-24.8）ppb 和 20.0（17.0-23.6）ppb（P=0.18）。我们发现，组内相关系数为 0.96（0.94-0.97），一致性较好，平均差值为 4%（95%置信区间为-43%至+90%）。
新算法可将潮气呼吸 FeNO 值转换为与 50ml/sec 恒流条件下单口气 FeNO 匹配的值。该算法为在学龄前儿童和不合作患者中进行标准化 FeNO 测量开辟了道路。
