BACKGROUND Evaluating expiratory airway function in infants is challenging, as the gold standard, the raised-volume rapid thoraco-abdominal compression technique is technically difficult and has a high failure rate. RESEARCH QUESTION Are measurements obtained during passive expiration from total lung capacity correlated with forced expiration measurements obtained by the raised-volume technique in infants? STUDY DESIGN AND METHODS This observational retrospective analysis included infants born ≥ 36 weeks gestation who underwent pulmonary function testing using the raised-volume rapid thoraco-abdominal compression technique at Hadassah Medical Centre between January 2011 and December 2019. Technically acceptable forced and passive flow-volume curve measurements were included in the analysis. RESULTS Out of 296 eligible infants, 276 (93%) had technically acceptable passive flow-volume curves while 226 (76%) had acceptable forced curves (p<0.001). The success rate of producing an acceptable curve was 70% for the passive curves and 39% for forced curves (p < 0.001). The Spearman correlation coefficients of vital capacity, expiratory volumes at 0.5 second, maximal expiratory flows, and expiratory flows at 50%, 75% and 85% of vital capacity were 0.92, 0.72, 0.83, 0.66, 0.67, 0.68, respectively (n= 226; p<0.001 for all). The correlation remained high regardless of the level of expiratory airway obstruction, gender or age. The mean inter-maneuver coefficients of variation were fairly low for both methods (5.2% vs 5.4%, p=NS). INTERPRETATION The passive flow-volume curve offers reliable and reproducible data with high correlation to the forced flow-volume curve. Therefore, the passive flow-volume curve can serve as an alternative tool in evaluating expiratory airway function in infants.

中文翻译：

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总肺活量的被动呼气可以估计婴儿的呼气功能：一项回顾性研究。


背景 评估婴儿的呼气道功能具有挑战性，作为金标准，提高容量的快速胸腹加压技术在技术上很困难，失败率很高。研究问题：被动呼气期间从总肺活量中获得的测量值是否与婴儿通过提高容量技术获得的用力呼气测量值相关？研究设计和方法 本观察性回顾性分析包括 2011 年 1 月至 2019 年 1≥2 月期间在 Hadassah 医疗中心使用增高容量快速胸腹加压技术进行肺功能测试的妊娠 36 周出生的婴儿。分析中包括技术上可接受的强制和被动流量-体积曲线测量。结果 在 296 名符合条件的婴儿中，276 名 （93%） 具有技术上可接受的被动流量-体积曲线，而 226 名 （76%） 具有可接受的受力曲线 （p<0.001）。被动曲线产生可接受曲线的成功率为 70%，强制曲线为 39% （p < 0.001）。肺活量、0.5 秒呼气量、最大呼气流量和肺活量 50%、75% 和 85% 时的呼气流量的 Spearman 相关系数分别为 0.92、0.72、0.83、0.66、0.67、0.68 （n= 226;p<0.001）。无论呼气道阻塞的程度、性别或年龄如何，相关性都很高。两种方法的平均操作间变异系数相当低 （5.2% vs 5.4%，p=NS）。解释被动流量-体积曲线提供可靠且可重复的数据，与强制流量-体积曲线高度相关。 因此，被动流量-体积曲线可以作为评估婴儿呼气道功能的替代工具。