Evaluation of Carbon-dioxide Rebreathing During Exercise With the Increasing Ventilation Assisted by Noninvasive Ventilation With a Dual-limb Circuit
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 8
- 试验地点
- 1
- 主要终点
- fractional concentration of inspired CO2
研究概览
简要总结
Ventilated by a single-limb tubing with PEV caused CO2 rebreathing to COPD patients during exercise with the increasing ventilation. The aim of this study was to evaluate whether CO2 rebreathing could be avoided with the use of the dual-limb circuit, to provide a theoretical basis of more rational clinical application of NIV in the setting of increasing ventilation(eg, after exercise).
详细描述
Exercise training is a key component of pulmonary rehabilitation. It has shown signifcant improvements in both exercise tolerance and quality of life in patients with COPD. The intensity of exercise training is of great importance to yield a true physiologic effect. However, in patients with severe COPD, exertional dyspnea and leg fatigue make it impossible for the patient to maintain intensity of training for enough time to achieve a physiologic training effect. NIV has been reported to be used as support for exercise to improve exercise tolerance and respiratory performances in patients with mild-to-severe COPD with inconsistent results. Evidence from previous studies have suggested that NIV with a single-limb circuit with Whisper Swivel II expiratory valve or Plateau exhalation valve assisted during exercise in patients with COPD caused CO2 rebreathing. CO2 rebreathing may have a negative impact on efficacy. Previous studies have proved that exercise tolerance was improved ventilated by NIV with a dual-limb circuit. In theory, NIV with a dual-limb circuit consists of one inhalation limb that introduces air into the patient's airways and one exhalation limb that leads exhaled gas outside of the airways, there is no risk of rebreathing. However, there was no report on whether there's no risk of rebreathing in COPD patients ventilated during exercise by a dual-limb circuit. Therefore, the aim of the study was to determine whether there was no CO2 rebreathing occurred assisted with NIV with dual-limb circuit in patients with stable severe COPD after exercise with exertional dyspnea.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 40 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •presented clinically stable (no exacerbation in the 4 weeks prior to study
- •participation or with no change in medications);
- •physician diagnosed COPD, forced expiratory volume in 1s (FEV1) < 50% predicted; dyspnea as a main symptom that limited daily activities.
排除标准
- •subjects with obvious pulmonary bullae demonstrated by chest CT scan or X-ray; examination or facial trauma/malformation, recent facial, upper airway or upper gastrointestinal tract surgery, that would preclude receiving NIV therapy;
- •a history of coronary artery disease or cardiac arrhythmias or potential electrocardiographic alterations;
- •a history of uncontrolled hypertension, or other respiratory diseases;
- •patients with musculoskeletal or neurological disorders;
- •failure to comply with the research protocol.
研究组 & 干预措施
dual-limb NIV
A maximal cycle exercise test with the participants assisted by BiPAP (Servo i, Maquet, Siemens) receiving 10 cmH2O pressure support in addition to oxygen therapy. During the test, breathing pattern, inspiratory flow of the inhalation limb and expiratory flow of the exhalation limb, fractional concentration of inspired CO2 (FiCO2) of the inspiratory line was measured for each breath were recorded.
干预措施: dual-limb NIV (Device)
结局指标
主要结局
fractional concentration of inspired CO2
时间窗: Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process.
FiCO2
次要结局
- expiratory flow of the exhalation limb(Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process.)
- breathing pattern(Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process.)
- inspiratory flow of the inhalation limb(Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process.)
研究者
Yonger Ou
Principal Investigator
Guangzhou Institute of Respiratory Disease