Division of Neonatology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ont., Canada.
Neonatology. 2013;103(3):161-5. doi: 10.1159/000345613. Epub 2012 Dec 19.
Noninvasive ventilation has been used increasingly in recent years to minimize the duration of endotracheal mechanical ventilation in neonates due to its association with lung injury. Nasal high-frequency oscillation (nHFO) is a relatively new noninvasive modality but evidence for its use is limited.
The goal of this study was to compare the CO2 clearance efficacy of nHFO and noninvasive positive pressure ventilation (NIPPV) in a neonatal lung model.
DESIGN/METHODS: A newborn mannequin with dimensions and anatomy similar to a term infant was utilized. It was connected to a commercially available neonatal mechanical ventilator using a manufacturer-provided nasal adaptor. Various modes of noninvasive ventilation were compared as CO2 clearance was measured at the oropharynx by an end-tidal CO2 analyzer following the addition of a known amount of CO2 into the lung. Measurements were obtained at two different lung compliances using nHFO and compared with nCMV and nasal continuous positive airway pressure (nCPAP) as a control. Pressures near the nasal adaptor and the larynx were simultaneously measured with in-line pressure transducers.
Whereas no CO2 elimination was observed under nCPAP, its clearance with nHFO was 3-fold greater as compared to NIPPV. On nHFO, CO2 clearance was inversely proportional to frequency and maximal at 6 and 8 Hz. At a lower lung compliance, CO2 clearance was significantly higher at 6 Hz as compared to 10 Hz. During nHFO set to deliver a MAP of 10.0, we documented pressures of 7.2 ± 0.3 at the nasal adaptor and only 2.3 ± 0.3 cm H2O at the larynx.
Nasal HFO is effective and superior to NIPPV at lung CO2 elimination in a newborn mannequin model. The use of nHFO as the preferred mode of noninvasive ventilation warrants further clinical studies.
近年来，由于与肺损伤有关，无创通气越来越多地用于减少新生儿气管内机械通气的持续时间。鼻高频振荡（nHFO）是一种相对较新的无创方式，但证据有限。
本研究旨在比较 nHFO 和无创正压通气（NIPPV）在新生儿肺模型中的 CO2 清除效果。
设计/方法：使用与足月婴儿尺寸和解剖结构相似的新生婴儿模型。它通过制造商提供的鼻适配器与市售的新生儿呼吸机连接。在向肺部中加入已知量的 CO2 后，通过测量口腔中的终末 CO2 分析仪来测量 CO2 清除率，比较各种无创通气模式。在两种不同的肺顺应性下进行测量，并与 nCMV 和鼻持续气道正压通气（nCPAP）进行比较作为对照。通过在线压力传感器同时测量靠近鼻适配器和喉部的压力。
nCPAP 下未观察到 CO2 消除，而 nHFO 的清除率是 NIPPV 的 3 倍。在 nHFO 下，CO2 清除率与频率成反比，在 6 和 8 Hz 时达到最大值。在较低的肺顺应性下，6 Hz 时的 CO2 清除率明显高于 10 Hz。在 nHFO 设置为输送 10.0 的 MAP 时，我们记录到鼻适配器处的压力为 7.2 ± 0.3，而喉部的压力仅为 2.3 ± 0.3 cm H2O。
在新生婴儿模型中，nHFO 是一种有效且优于 NIPPV 的肺 CO2 清除方法。nHFO 作为首选无创通气模式的使用值得进一步的临床研究。
