PDF(Pubmed)
Abstract：
BACKGROUND: Closed-loop oxygen control systems automatically adjust the fraction of inspired oxygen (FiO2) to maintain oxygen saturation (SpO2) within a predetermined target range. Their performance with low and high-flow oxygen therapies, but not with non-invasive ventilation, has been established. We compared the effect of automated oxygen on achieving and maintaining a target SpO2 range with nasal high flow (NHF), bilevel positive airway pressure (bilevel) and continuous positive airway pressure (CPAP), in stable hypoxaemic patients with chronic cardiorespiratory disease.
METHODS: In this open-label, three-way cross-over trial, participants with resting hypoxaemia (n=12) received each of NHF, bilevel and CPAP treatments, in random order, with automated oxygen titrated for 10 min, followed by 36 min of standardised manual oxygen adjustments. The primary outcome was the time taken to reach target SpO2 range (92%-96%). Secondary outcomes included time spent within target range and physiological responses to automated and manual oxygen adjustments.
RESULTS: Two participants were randomised to each of six possible treatment orders. During automated oxygen control (n=12), the mean (±SD) time to reach target range was 114.8 (±87.9), 56.6 (±47.7) and 67.3 (±61) seconds for NHF, bilevel and CPAP, respectively, mean difference 58.3 (95% CI 25.0 to 91.5; p=0.002) and 47.5 (95% CI 14.3 to 80.7; p=0.007) seconds for bilevel and CPAP versus NHF, respectively. Proportions of time spent within target range were 68.5% (±16.3), 65.6% (±28.7) and 74.7% (±22.6) for NHF, bilevel and CPAP, respectively.Manually increasing, then decreasing, the FiO2 resulted in similar increases and then decreases in SpO2 and transcutaneous carbon dioxide (PtCO2) with NHF, bilevel and CPAP.
CONCLUSIONS: The target SpO2 range was achieved more quickly when automated oxygen control was initiated with bilevel and CPAP compared with NHF while time spent within the range across the three therapies was similar. Manually changing the FiO2 had similar effects on SpO2 and PtCO2 across each of the three therapies.
BACKGROUND: ACTRN12622000433707.
METHODS: In this open-label, three-way cross-over trial, participants with resting hypoxaemia (n=12) received each of NHF, bilevel and CPAP treatments, in random order, with automated oxygen titrated for 10 min, followed by 36 min of standardised manual oxygen adjustments. The primary outcome was the time taken to reach target SpO2 range (92%-96%). Secondary outcomes included time spent within target range and physiological responses to automated and manual oxygen adjustments.
RESULTS: Two participants were randomised to each of six possible treatment orders. During automated oxygen control (n=12), the mean (±SD) time to reach target range was 114.8 (±87.9), 56.6 (±47.7) and 67.3 (±61) seconds for NHF, bilevel and CPAP, respectively, mean difference 58.3 (95% CI 25.0 to 91.5; p=0.002) and 47.5 (95% CI 14.3 to 80.7; p=0.007) seconds for bilevel and CPAP versus NHF, respectively. Proportions of time spent within target range were 68.5% (±16.3), 65.6% (±28.7) and 74.7% (±22.6) for NHF, bilevel and CPAP, respectively.Manually increasing, then decreasing, the FiO2 resulted in similar increases and then decreases in SpO2 and transcutaneous carbon dioxide (PtCO2) with NHF, bilevel and CPAP.
CONCLUSIONS: The target SpO2 range was achieved more quickly when automated oxygen control was initiated with bilevel and CPAP compared with NHF while time spent within the range across the three therapies was similar. Manually changing the FiO2 had similar effects on SpO2 and PtCO2 across each of the three therapies.
BACKGROUND: ACTRN12622000433707.
摘要：
背景：闭环氧气控制系统自动调节吸入氧气（FiO2）的分数，以将氧饱和度（SpO2）保持在预定的目标范围内。他们在低流量和高流量氧气疗法中的表现，但没有无创通气，已经建立。我们比较了自动氧气在实现和维持目标SpO2范围与鼻高流量（NHF）的影响，双水平气道正压（双水平）和持续气道正压（CPAP），在慢性心肺疾病的稳定低氧血症患者中。
方法：在此开放标签中，三方交叉审判，静息低氧血症的参与者(n=12)接受了NHF，双层和CPAP治疗，以随机顺序，自动滴定氧气10分钟，然后进行36分钟的标准化手动氧气调节。主要结果是达到目标SpO2范围（92％-96％）所需的时间。次要结果包括在目标范围内花费的时间以及对自动和手动氧气调节的生理反应。
结果：两名参与者被随机分为六个可能的治疗顺序。在自动氧气控制期间（n=12），达到目标范围的平均（±SD）时间为114.8（±87.9），NHF为56.6（±47.7）和67.3（±61）秒，双层和CPAP，分别,双层和CPAP与NHF的平均差为58.3（95％CI25.0至91.5；p=0.002）和47.5（95％CI14.3至80.7；p=0.007）秒，分别。在目标范围内花费的时间比例为68.5%(±16.3)，NHF为65.6%(±28.7)和74.7%(±22.6)，双层和CPAP，分别。手动增加,然后减少，FiO2导致SpO2和经皮二氧化碳（PtCO2）与NHF相似的增加，然后降低，双层和CPAP。
结论：与NHF相比，当使用双水平和CPAP启动自动氧气控制时，目标SpO2范围更快地实现，而在这三种疗法范围内花费的时间相似。在三种疗法中，手动改变FiO2对SpO2和PtCO2的影响相似。
背景：ACTRN12622000433707。
方法：在此开放标签中，三方交叉审判，静息低氧血症的参与者(n=12)接受了NHF，双层和CPAP治疗，以随机顺序，自动滴定氧气10分钟，然后进行36分钟的标准化手动氧气调节。主要结果是达到目标SpO2范围（92％-96％）所需的时间。次要结果包括在目标范围内花费的时间以及对自动和手动氧气调节的生理反应。
结果：两名参与者被随机分为六个可能的治疗顺序。在自动氧气控制期间（n=12），达到目标范围的平均（±SD）时间为114.8（±87.9），NHF为56.6（±47.7）和67.3（±61）秒，双层和CPAP，分别,双层和CPAP与NHF的平均差为58.3（95％CI25.0至91.5；p=0.002）和47.5（95％CI14.3至80.7；p=0.007）秒，分别。在目标范围内花费的时间比例为68.5%(±16.3)，NHF为65.6%(±28.7)和74.7%(±22.6)，双层和CPAP，分别。手动增加,然后减少，FiO2导致SpO2和经皮二氧化碳（PtCO2）与NHF相似的增加，然后降低，双层和CPAP。
结论：与NHF相比，当使用双水平和CPAP启动自动氧气控制时，目标SpO2范围更快地实现，而在这三种疗法范围内花费的时间相似。在三种疗法中，手动改变FiO2对SpO2和PtCO2的影响相似。
背景：ACTRN12622000433707。
