Divisao de Pneumologia, Instituto do Coracao, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil.
Divisao de Anestesiologia, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, Brazil.
Respir Care. 2019 Nov;64(11):1416-1421. doi: 10.4187/respcare.06746. Epub 2019 Jul 23.
Noninvasive ventilation (NIV) reduces intubation and mortality in patients with COPD exacerbation who present with respiratory failure, and the type of mask may affect its success. Our objective was to compare the performance of 3 different NIV masks in a lung model.
We set the lung simulator mechanics and respiratory rate, and tested a small oronasal mask, a total face mask, and a large oronasal mask. We added CO at a constant rate into the system and monitored the end-tidal carbon dioxide. We used a mechanical ventilator to deliver NIV in 8 different combinations of inspiratory effort, pressure support, and expiratory positive airway pressure. We measured end-tidal carbon dioxide mask leakage, tidal volume, trigger time, time to achieve 90% of the inspiratory target during inspiration, and excess inspiratory time.
We presented the mean ± SD of the 8 simulated conditions for each mask. The mean ± SD leakage was higher for the total face mask (51 ± 6 L/min) than for the small oronasal mask (37 ± 5 L/min) and for the large oronasal mask (21 ± 3 L/min), < .001; but end-tidal carbon dioxide and tidal volume were similar. The mean ± SD 90% of the inspiratory target during inspiration was faster for the small oronasal mask (585 ± 49 ms) compared with the large oronasal (647 ± 107 ms) and total face mask (851 ± 105 ms), < .001, all other variables were similar.
In this model, we found that the type of mask had no impact on CO washout or on most synchrony variables.
无创通气（NIV）可降低伴有呼吸衰竭的 COPD 加重患者的插管率和死亡率，而面罩类型可能会影响其效果。我们的目的是比较 3 种不同 NIV 面罩在肺模型中的性能。
我们设定肺模拟器的力学和呼吸频率，并测试了小口鼻面罩、全面罩和大口鼻面罩。我们以恒定的速率向系统中添加 CO，并监测呼气末二氧化碳。我们使用机械呼吸机以 8 种不同的吸气努力、压力支持和呼气正压通气组合进行 NIV。我们测量呼气末二氧化碳面罩泄漏、潮气量、触发时间、吸气期间达到吸气目标 90%的时间和吸气过冲时间。
我们为每个面罩呈现了 8 种模拟条件的平均值±SD。全面罩的平均±SD 泄漏（51±6L/min）高于小口鼻面罩（37±5L/min）和大口鼻面罩（21±3L/min），<0.001；但呼气末二氧化碳和潮气量相似。小口鼻面罩达到吸气目标 90%的平均±SD 时间（585±49ms）快于大口鼻面罩（647±107ms）和全面罩（851±105ms），<0.001，所有其他变量均相似。
在这个模型中，我们发现面罩类型对 CO 洗脱或大多数同步变量没有影响。
