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Physiological Effects of Different Preoxygenation Strategies (PREOXY II)

2026年5月6日 更新者：Simon Rauch、Institute of Mountain Emergency Medicine

Physiological Effects of Different Preoxygenation Strategies in Adults and Children: A Comparative Study of NRM and BVM With and Without PEEP

The goal of this clinical trial is to evaluate the performance and physiological effects of different preoxygenation devices in healthy adult and pediatric volunteers (children aged 5-12 years). The study aims to determine how these devices influence oxygen delivery, airway pressure, and cardiopulmonary physiology during preoxygenation.

The main questions it aims to answer are:

  • What fraction of inspired oxygen (FiO₂) is delivered by non-rebreather masks (NRM) compared to bag-valve masks (BVM) with and without positive end-expiratory pressure (PEEP)?
  • How do these devices differ in terms of generated PEEP, inspiratory effort, and their effects on lung ventilation and cardiac function?

Researchers will compare NRM, BVM without PEEP, and BVM with PEEP (each with or without supplemental oxygen via nasal cannula) to evaluate differences in oxygenation and physiological effects.

Participants will:

  • Complete multiple 3-minute preoxygenation sessions using each device in randomized order
  • Breathe spontaneously through each device, with or without additional oxygen via nasal cannula
  • Undergo non-invasive monitoring of oxygen concentration (FiO₂), respiratory parameters, airway pressures, and ultrasound assessment of the lungs, diaphragm, and heart
  • Perform a brief breath-holding maneuver to assess airway pressure generation

研究概览

地位

招聘中

条件

干预/治疗

详细说明

Hypoxemia is a frequent and potentially life-threatening complication during advanced airway management, associated with adverse outcomes such as hypoxic brain injury, cardiovascular collapse, and death. Effective preoxygenation is essential to increase oxygen reserves and prolong safe apnea time during intubation. Although several devices are routinely used for preoxygenation, including non-rebreather masks (NRM) and bag-valve masks (BVM) with or without positive end-expiratory pressure (PEEP), important uncertainties remain regarding their actual performance and physiological effects.

Current evidence suggests that techniques providing PEEP may improve oxygenation by increasing functional residual capacity, enhancing ventilation of dependent lung regions, and reducing ventilation-perfusion mismatch. However, the relative contribution of FiO₂ delivery versus PEEP, as well as the physiological effects on respiratory mechanics and cardiovascular function, are not fully understood. In addition, it remains unclear whether BVM devices without a dedicated PEEP valve can generate measurable PEEP, and whether patients can generate sufficient inspiratory effort to effectively operate BVM valves without assisted ventilation. Data in pediatric populations are particularly limited.

This randomized crossover study is designed to systematically evaluate the performance of commonly used preoxygenation devices under controlled conditions in healthy adult and pediatric volunteers. By comparing NRM, BVM without PEEP, and BVM with PEEP-with and without supplemental oxygen via nasal cannula-the study aims to characterize differences in oxygen delivery, airway pressure generation, inspiratory effort, and their physiological impact.

The study will focus on key physiological domains, including oxygenation (FiO₂), respiratory mechanics (tidal volume, airway pressures, and diaphragm activity), lung aeration (with particular attention to dependent lung regions), and cardiovascular responses (including right ventricular dimensions and function). Measurements will be obtained using non-invasive monitoring techniques, including gas analysis and ultrasound.

The crossover design allows within-subject comparisons across all study conditions, minimizing inter-individual variability and enabling precise assessment of device-related effects. The findings of this study are expected to improve understanding of the mechanisms and physiological consequences of preoxygenation strategies, with potential implications for optimizing airway management practices in both adult and pediatric populations.

研究类型

介入性

注册 (估计的)

30

阶段

  • 不适用

联系人和位置

本节提供了进行研究的人员的详细联系信息，以及有关进行该研究的地点的信息。

学习联系方式

研究联系人备份

学习地点

  • 意大利
    • BZ
      • Bolzano、BZ、意大利、39100
        • 招聘中
        • Eurac research, Institute of mountain emergency medicine
        • 接触：
        • 接触：
        • 副研究员：
          • Ruth Martintoni
        • 首席研究员：
          • Simon Rauch, MD, PhD
        • 首席研究员：
          • Giulia Roveri, MD

参与标准

研究人员寻找符合特定描述的人，称为资格标准。这些标准的一些例子是一个人的一般健康状况或先前的治疗。

资格标准

适合学习的年龄

  • 孩子
  • 成人
  • 年长者

接受健康志愿者

是的

描述

Inclusion Criteria:

  • Adults with an American Society of Anesthesiologists (ASA) physical status score ≤ 2
  • Children aged 5 to 12 years with an ASA physical status score ≤ 2
  • Ability (or legal guardian ability) to provide written informed consent

Exclusion Criteria:

  • Children aged < 5 years or 13 to 18 years
  • ASA physical status score > 2
  • Body mass index (BMI) ≥ 30 kg/m²
  • Known airway pathology or anatomical abnormality that could affect mask fit, ventilation, or oxygenation
  • Presence of an active airway infection at the time of the study
  • Pregnancy
  • Refusal or inability to provide informed consent

学习计划

本节提供研究计划的详细信息，包括研究的设计方式和研究的衡量标准。

研究是如何设计的？

设计细节

  • 主要用途：预防
  • 分配：随机化
  • 介入模型：交叉作业
  • 屏蔽：单身的

武器和干预

参与者组/臂
干预/治疗
实验性的：Nasal Cannula (NC)
Preoxygenation over 3 minutes with a nasal cannula (NC) with supplemental oxygen delivered at 15 L/min, during spontaneous breathing.
设备：Nasal cannula (NC)
Preoxygenation performed using a nasal cannula delivering supplemental oxygen at a flow rate of 15 L/min, without the use of an additional mask or ventilation device, during spontaneous breathing.
实验性的：Non-rebreather facemask (NRM)
Preoxygenation over 3 minutes with a Non-rebreather facemask (NRM) with supplemental oxygen delivered at 15 L/min, during spontaneous breathing.
设备：Non-rebreather mask (NRM)
Preoxygenation performed using a non-rebreather mask with reservoir, delivering oxygen at a flow rate of 15 L/min. The mask is fitted to ensure an optimal seal, and participants breathe spontaneously without assisted ventilation.
实验性的：Non-rebreather facemask (NRM) plus Nasal Cannula (NC)
Preoxygenation for 3 minutes using a non-rebreather mask (NRM) combined with a nasal cannula delivering supplemental oxygen at 15 L/min for each device, during spontaneous breathing.
设备：Non-rebreather mask (NRM) plus Nasal cannula (NC)
Preoxygenation performed using a non-rebreather mask with reservoir, delivering oxygen at a flow rate of 15 L/min, combined with a nasal cannula delivering supplemental oxygen at 15 L/min. The mask is fitted to ensure an optimal seal, and participants breathe spontaneously without assisted ventilation.
实验性的：Bag valve mask (BVM)
Preoxygenation for 3 minutes using a bag-valve-mask (BVM) with supplemental oxygen delivered at 15 L/min, during spontaneous breathing.
设备：Bag-valve mask (BVM) without PEEP
Preoxygenation performed using a bag-valve mask without a PEEP valve, delivering oxygen at a flow rate of 15 L/min. The mask is held with a two-handed technique to ensure an airtight seal, without providing assisted ventilation, allowing spontaneous breathing.
实验性的：Bag valve mask (BVM) plus Nasal cannula (NC)
Preoxygenation for 3 minutes using a bag -valve-mask (BVM) combined with a nasal cannula delivering supplemental oxygen at 15 L/min for each device, during spontaneous breathing.
设备：Bag-valve mask (BVM) without PEEP + nasal cannula (NC)
Preoxygenation performed using a bag-valve mask without a PEEP valve, delivering oxygen at a flow rate of 15 L/min, combined with a nasal cannula delivering supplemental oxygen at 15 L/min. The mask is held with a two-handed technique to ensure an airtight seal, without providing assisted ventilation, allowing spontaneous breathing.
实验性的：Bag valve mask (BVM) plus PEEP
Preoxygenation for 3 minutes using a bag-valve mask (BVM) with positive end-expiratory pressure (PEEP) set at 10 cmH₂O and supplemental oxygen delivered at 15 L/min, during spontaneous breathing.
设备：Bag-valve mask (BVM) with PEEP
Preoxygenation performed using a bag-valve mask equipped with a PEEP valve set at 10 cmH₂O, delivering oxygen at a flow rate of 15 L/min. The mask is held with a two-handed technique to ensure an airtight seal, without assisted ventilation, during spontaneous breathing.
实验性的：Bag valve mask (BVM) plus PEEP plus Nasal Cannula (NC)
Preoxygenation for 3 minutes using a bag-valve mask (BVM) with positive end-expiratory pressure (PEEP) set at 10 cmH₂O, combined with a nasal cannula delivering supplemental oxygen at 15 L/min for each device, during spontaneous breathing.
设备：Bag-valve mask (BVM) with PEEP + nasal cannula (NC)
Preoxygenation performed using a bag-valve mask equipped with a PEEP valve set at 10 cmH₂O, delivering oxygen at a flow rate of 15 L/min, combined with a nasal cannula delivering supplemental oxygen at 15 L/min. The mask is held with a two-handed technique to ensure an airtight seal, without assisted ventilation, during spontaneous breathing.

研究衡量的是什么？

主要结果指标

结果测量
措施说明
大体时间
Difference in fraction of inspired oxygen (FiO₂) between preoxygenation devices
大体时间：During each 3-minute preoxygenation session
Fraction of inspired oxygen (FiO₂) delivered during preoxygenation will be continuously measured at the airway opening using a gas analyzer. FiO₂ values will be recorded breath-by-breath during each 3-minute preoxygenation session under all study conditions. The primary outcome is the difference in mean FiO₂ achieved between the different preoxygenation devices (non-rebreather mask, bag-valve mask without PEEP, and bag-valve mask with PEEP), with and without supplemental oxygen via nasal cannula.
During each 3-minute preoxygenation session

次要结果测量

结果测量
措施说明
大体时间
Positive end-expiratory pressure (PEEP) generated during preoxygenation
大体时间：During each 3-minute preoxygenation session
Airway pressures will be continuously measured to quantify the presence and magnitude of PEEP generated during preoxygenation with bag-valve mask (BVM) with and without a dedicated PEEP valve, with and without nasal cannula oxygen supplementation.
During each 3-minute preoxygenation session
Inspiratory effort required to open the BVM valve
大体时间：During each 3-minute preoxygenation session
The negative pressure required to open the BVM valve will be measured using airway pressure monitoring, and diaphragm ultrasound parameters (thickening fraction and excursion) will be used as surrogate markers of inspiratory effort.
During each 3-minute preoxygenation session
Ventilation of dependent lung regions
大体时间：During each 3-minute preoxygenation session
Lung ultrasound will be used to assess regional ventilation of dependent lung areas, with findings quantified using a validated scoring system to compare the effects of preoxygenation with and without PEEP.
During each 3-minute preoxygenation session
Correlation between FiO₂ and tidal volume
大体时间：During each 3-minute preoxygenation session
The relationship between fraction of inspired oxygen (FiO₂) and tidal volume during preoxygenation will be assessed using continuous, breath-by-breath measurements.
During each 3-minute preoxygenation session
Cardiac output
大体时间：Baseline and at the end of each 3-minute preoxygenation session
Changes in cardiac output (l/min/m²) will be assessed using echocardiography before and after preoxygenation to evaluate the hemodynamic effects of different devices and PEEP.
Baseline and at the end of each 3-minute preoxygenation session
Changes in right ventricular dimensions
大体时间：Baseline and at the end of each 3-minute preoxygenation session
Changes in right ventricular dimensions (mm) will be assessed using echocardiography before and after preoxygenation to evaluate the hemodynamic effects of different devices and PEEP.
Baseline and at the end of each 3-minute preoxygenation session
Right ventricular strain
大体时间：Baseline and at the end of each 3-minute preoxygenation session
Changes in right ventricular strain (%) will be assessed using echocardiography before and after preoxygenation to evaluate the hemodynamic effects of different devices and PEEP.
Baseline and at the end of each 3-minute preoxygenation session

其他结果措施

结果测量
措施说明
大体时间
Airway pressure during breath-holding maneuver
大体时间：Immediately following the preoxygenation session with bag-valve mask (with or without PEEP)
Airway pressure generated during a brief voluntary breath-holding maneuver will be measured when oxygen is delivered via nasal cannula under a bag-valve mask (with or without PEEP), to assess potential continuous positive airway pressure generation.
Immediately following the preoxygenation session with bag-valve mask (with or without PEEP)

合作者和调查者

在这里您可以找到参与这项研究的人员和组织。

赞助

Institute of Mountain Emergency Medicine

调查人员

  • 首席研究员：Simon Rauch、Eurac research, Institute of mountain emergency medicine

出版物和有用的链接

负责输入研究信息的人员自愿提供这些出版物。这些可能与研究有关。

一般刊物

研究记录日期

这些日期跟踪向 ClinicalTrials.gov 提交研究记录和摘要结果的进度。研究记录和报告的结果由国家医学图书馆 (NLM) 审查，以确保它们在发布到公共网站之前符合特定的质量控制标准。

研究主要日期

学习开始 (估计的)

2026年5月23日

初级完成 (估计的)

2026年6月30日

研究完成 (估计的)

2026年6月30日

研究注册日期

首次提交

2026年4月26日

首先提交符合 QC 标准的

2026年4月26日

首次发布 (实际的)

2026年5月4日

研究记录更新

最后更新发布 (实际的)

2026年5月8日

上次提交的符合 QC 标准的更新

2026年5月6日

最后验证

2026年4月1日

更多信息

与本研究相关的术语

关键字

其他相关的 MeSH 术语

其他研究编号

  • PREOXY II

计划个人参与者数据 (IPD)

计划共享个人参与者数据 (IPD)？

不

药物和器械信息、研究文件

研究美国 FDA 监管的药品

不

研究美国 FDA 监管的设备产品

不

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