The Effect of Asymmetrical vs. Symmetrical High Flow Nasal Cannula on the Work of Breathing: A Randomised Cross-over Study
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 发起方
- 入组人数
- 30
- 试验地点
- 1
- 主要终点
- Change in the pressure time product after the use of symmetrical high flow nasal interface for 15 minutes.
研究概览
简要总结
The goal of this study randomized single-center crossover study is to evaluate the impact of asymmetrical versus symmetrical nasal high flow (NHF) therapy on work of breathing (WOB). The main question it aims to answer are:
- Does the asymmetrical NHF interface improve the work of breathing compared to the symmetrical NHF interface? Researchers will compare the symmetrical NHF interface to the symmetrical NHF interface to see if the the asymmetrical interface has a greater impact on the work of breathing.
Participants will :
- receive NHF via both interfaces (FiO₂ 0.21, 50 L/min) for 15 minutes, in random order, with esophageal pressure monitoring and bioelectrical impedance analysis performed.
- baseline characteristics will me monitored throughout the interventions
- Esophageal pressure and minute ventilation will be monitored.
详细描述
Each participant will undergo all phases of the study while seated comfortably, breathing room air. Vital signs, including blood pressure, heart rate, and peripheral oxygen saturation (%SpO₂), will be continuously monitored and recorded throughout.
Respiratory mechanics will be assessed using esophageal pressure (Pes) monitoring. A thin latex balloon catheter (10 cm long, 3-5 cm circumference; Cooper surgical, USA), filled with 0.5 mL of air, will be placed in the mid-esophagus (~45 cm from the nares) and will be connected to a pressure transducer (RSS-100HR, Hans Rudolph Inc., USA). Correct positioning will be confirmed by observing equal fluctuations in Pes and airway pressure (Paw) during occluded breaths. Balloon integrity will be verified before, after, and as needed during the procedure.
Participants will be instructed to breathe quietly on room air (FiO₂ 0.21) to allow for baseline assessment. Volume will be recorded using a heated pneumotachometer (Series 3813; Hans Rudolph Inc., USA) and the Research Pneumotach System (RSS100-HR), sampling at 50 Hz, a sampling rate exceeding the Nyquist criterion for respiratory signals. A bioelectrical impedance technology device (ExSpiron, Respiratory Motion Inc., Waltham, MA) will then be attached around the chest to assess lung volume changes.
Participants will then be randomized in a 1:1 ratio to one of two intervention sequences using a computer-generated randomization schedule.
- Sequence 1: Symmetrical NHF Interface - 3-minute washout period - Asymmetrical NHF Interface
- Sequence 2: Asymmetrical NHF Interface - 3-minute washout period - Symmetrical NHF Interface In the seated position, participants will both 15-minute phases, separated by a 3-minute washout period to prevent residual effects. During the "Symmetrical Interface" phase, participants will breathe using the conventional symmetrical NHF cannula, and during the asymmetrical phase, the asymmetrical interface (DUET, Fisher and Paykel Healthcare, Auckland, New Zealand) will be used. High-flow oxygen will be delivered using a commercial system (AIRVO 3; Fisher and Paykel Healthcare, Auckland, New Zealand) set at a flow of 50 L/min, temperature of 37°C, and FiO₂ of 0.21.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Single (Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •age ≥18 years old
- •absence of symptoms and signs of respiratory failure (SpO2>95% at FiΟ2 0.21)
排除标准
- •SpO2<94% at FiΟ2 0.21
- •neuromuscular disease
- •contraindications to esophageal pressure monitoring (e.g., uncontrolled coagulopathy, esophageal disease, nasal trauma, allergy to local lidocaine)
研究组 & 干预措施
Recovery patients from respiratory disease - Asymmetric or conventional nasal high flow cannula
Patients recovered from acute respiratory disease will be randomized to NHF oxygen therapy with asymmetrical cannula or conventional cannula
干预措施: Asymmetric nasal cannula - DUET (Device)
Recovery patients from respiratory disease - Asymmetric or conventional nasal high flow cannula
Patients recovered from acute respiratory disease will be randomized to NHF oxygen therapy with asymmetrical cannula or conventional cannula
干预措施: Conventional nasal high flow cannula (Device)
Recovery patients from respiratory disease - Conventional or asymmetric nasal high flow cannula
Patients recovered from acute respiratory disease will be randomized to NHF oxygen therapy with conventional cannula or asymmetrical cannula
干预措施: Asymmetric nasal cannula - DUET (Device)
Recovery patients from respiratory disease - Conventional or asymmetric nasal high flow cannula
Patients recovered from acute respiratory disease will be randomized to NHF oxygen therapy with conventional cannula or asymmetrical cannula
干预措施: Conventional nasal high flow cannula (Device)
结局指标
主要结局
Change in the pressure time product after the use of symmetrical high flow nasal interface for 15 minutes.
时间窗: Baseline and 15 minutes
This outcome measures the change in the Pressure-Time Product (PTP) before and after the application of a symmetrical high-flow nasal interface (HFNI) in patients requiring noninvasive respiratory support. The PTP is a physiological index that reflects the work of breathing and respiratory muscle effort. It is calculated using airway pressure and inspiratory time data over a defined period. The primary goal is to assess whether the symmetrical HFNI leads to a measurable reduction in the PTP, indicating improved respiratory mechanics and decreased patient effort.
Change in the pressure time product after the use of asymmetrical nasal high flow interface for 15 minutes.
时间窗: Baseline and 15 minutes
This outcome measures the change in the Pressure-Time Product (PTP) before and after the application of a symmetrical high-flow nasal interface (HFNI) in patients requiring noninvasive respiratory support. The PTP is a physiological index that reflects the work of breathing and respiratory muscle effort. It is calculated using airway pressure and inspiratory time data over a defined period. The primary goal is to assess whether the asymmetrical HFNI leads to a measurable reduction in the PTP, indicating improved respiratory mechanics and decreased patient effort.
次要结局
未报告次要终点
研究者
Ioannis Pantazopoulos
Associate Professor of Respiratory & Emergency Medicine Faculty of Medicine, University of Thessaly, Greece
Larissa University Hospital