Noninvasive positive pressure ventilation (NPPV) is a major respiratory support technique for patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and carbon dioxide (CO₂) retention. However, the obvious dead space in available masks used for NPPV could easily lead to repeated CO₂ inhalation, which affects the correction of CO₂ retention.

To develop a face mask with two channel and constant leakage (TCCL) used for NPPV, and to examine its value in NPPV treatment of AECOPD patients with CO₂ retention.

Thirty patients with AECOPD and typeⅡ respiratory failure treated with NPPV were recruited from the ICU, the First Affiliated Hospital of Chongqing Medical University from 2020 to 2021, and equally randomized into an experimental group (using the TCCL mask) and an control group (using the traditional mask with an exhalation valve on the side for NPPV) . Treatment effectiveness was assessed using arterial partial pressure of oxygen (PaO₂) and partial pressure of carbon dioxide (PaCO₂) monitored at baseline, and at the end of 4, 8, 24, and 48 hours of NPPV treatment as well as 24 hours after NPPV cessation.

The two-way repeated measures ANOVA indicated that treatment time and treatment approach had no interactive effects on PaO₂ (P>0.05) . Treatment time produced significant main effects on PaO₂ (P<0.001) , while treatment approach did not (F=0.153, P=0.699) . In both groups, the level of PaO₂ at baseline was lower than that at the end of 4, 8, 24, and 48 hours of NPPV treatment and 24 hours after NPPV cessation (P<0.05) ; the level of PaO₂ at the end of 4 hours of treatment was lower than that measured at the subsequent four time points (P<0.05) ; the PaO₂ level at the end of 8 hours of treatment was lower than that at 48 hours of treatment and 24 hours after NPPV cessation (P<0.05) . The PaO₂ level at 24 hours of treatment was lower than that at 48 hours of treatment in the control group (P<0.05) . The PaO₂ level at 24 hours of treatment was lower than that at 48 hours of treatment and 24 hours after NPPV cessation in the experimental group (P<0.05) . But there was no significant difference in PaO₂ level measured at each time point between the groups (P>0.05) . Treatment time and treatment approach had no interactive effects on PaCO₂ (P>0.05) . Treatment time produced significant main effect on PaCO₂ (P<0.001) , treatment approach also exerted obvious effect on it (F=5.129, P=0.031) . Compared with the control group, the experimental group demonstrated lower PaCO₂ levels at the end of 4, 8 and 24 hours of treatment (P<0.05) . In both groups, the PaCO₂ level at baseline was higher than that at the end of 4, 8, 24, and 48 hours after NPPV treatment and 24 hours after NPPV cessation (P<0.05) . The PaCO₂ level at the end of 4 hours of treatment was higher than that measured at the subsequent four time points (P<0.05) . The PaCO₂ level at the end of 8 hours of treatment was higher than that measured at the subsequent three time points (P<0.05) . The PaCO₂ level of the control group at 24 hours of treatment was higher than that at 48 hours of treatment and 24 hours after NPPV cessation (P<0.05) . The PaCO₂ level in the experimental group at 24 or 48 hours of treatment was higher than that at 24 hours after NPPV cessation.

TCCL mask may contribute to rapid correction of CO₂ retention and effective improvement of oxygenation in AECOPD patients.

无创正压通气（NPPV）是治疗慢性阻塞性肺疾病急性加重（AECOPD）合并CO₂潴留患者的重要呼吸支持技术。但现有NPPV面罩内存在明显无效腔效应，容易导致CO₂重复呼吸而影响患者CO₂潴留的纠正。

研发一种具有双通道通气和恒定泄气量功能的NPPV面罩（即TCCL面罩），并探讨其在NPPV治疗AECOPD合并CO₂潴留患者中的价值。

选择重庆医科大学附属第一医院重症医学科2020—2021年收治的30例AECOPD合并Ⅱ型呼吸衰竭行NPPV治疗的患者为研究对象。根据不同的NPPV面罩类型随机分为试验组（n=15）和对照组（n=15）。试验组采用TCCL面罩；对照组采用传统NPPV面罩和侧孔型呼气阀的组合。监测两组NPPV治疗0 h、4 h、8 h、24 h、48 h及停止NPPV 24 h的动脉血氧分压（PaO₂）和二氧化碳分压（PaCO₂）水平。

两因素重复测量方差分析结果可见，时间和组间对PaO₂、PaCO₂不存在交互作用（P>0.05），时间对PaO₂、PaCO₂主效应显著（P<0.001），组间对PaO₂主效应不显著（F_组间=0.153，P_组间=0.699），组间对PaCO₂主效应显著（F_组间=5.129，P_组间=0.031）。两组治疗0 h的PaO₂水平均低于治疗4 h、8 h、24 h、48 h及停止NPPV 24 h（P<0.05）；两组治疗4 h的PaO₂水平均低于治疗8 h、24 h、48 h及停止NPPV 24 h（P<0.05）；两组治疗8 h的PaO₂水平均低于治疗48 h及停止NPPV 24 h（P<0.05）；对照组治疗24 h的PaO₂水平低于治疗48 h（P<0.05）；试验组治疗24 h的PaO₂水平低于治疗48 h及停止NPPV 24 h（P<0.05）；相同时间点两组间PaO₂水平比较，差异无统计学意义（P>0.05）。试验组治疗4 h、8 h、24 h的PaCO₂水平低于对照组（P<0.05）。两组治疗0 h时PaCO₂水平高于治疗4 h、8 h、24 h、48 h及停止NPPV 24 h（P<0.05），两组治疗4 h时PaCO₂水平高于治疗8 h、24 h、48 h及停止NPPV 24 h（P<0.05），两组治疗8 h的PaCO₂水平高于治疗24 h、48 h及停止NPPV 24 h（P<0.05）。对照组治疗24 h时PaCO₂水平高于治疗48 h及停止NPPV 24 h（P<0.05），试验组治疗24 h、48 h时PaCO₂水平高于治疗停止NPPV 24 h（P<0.05）。

TCCL面罩有助于快速纠正AECOPD患者的CO₂潴留，并能有效改善其血氧水平。