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Physiological Effects of Different Preoxygenation Strategies (PREOXY II)

6 maja 2026 zaktualizowane przez: 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

Przegląd badań

Szczegółowy opis

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.

Typ studiów

Interwencyjne

Zapisy (Szacowany)

30

Faza

  • Nie dotyczy

Kontakty i lokalizacje

Ta sekcja zawiera dane kontaktowe osób prowadzących badanie oraz informacje o tym, gdzie badanie jest przeprowadzane.

Kontakt w sprawie studiów

Kopia zapasowa kontaktu do badania

Lokalizacje studiów

    • BZ
      • Bolzano, BZ, Włochy, 39100
        • Rekrutacyjny
        • Eurac research, Institute of mountain emergency medicine
        • Kontakt:
        • Kontakt:
        • Pod-śledczy:
          • Ruth Martintoni
        • Główny śledczy:
          • Simon Rauch, MD, PhD
        • Główny śledczy:
          • Giulia Roveri, MD

Kryteria uczestnictwa

Badacze szukają osób, które pasują do określonego opisu, zwanego kryteriami kwalifikacyjnymi. Niektóre przykłady tych kryteriów to ogólny stan zdrowia danej osoby lub wcześniejsze leczenie.

Kryteria kwalifikacji

Wiek uprawniający do nauki

  • Dziecko
  • Dorosły
  • Starszy dorosły

Akceptuje zdrowych ochotników

Tak

Opis

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

Plan studiów

Ta sekcja zawiera szczegółowe informacje na temat planu badania, w tym sposób zaprojektowania badania i jego pomiary.

Jak projektuje się badanie?

Szczegóły projektu

  • Główny cel: Zapobieganie
  • Przydział: Randomizowane
  • Model interwencyjny: Zadanie krzyżowe
  • Maskowanie: Pojedynczy

Broń i interwencje

Grupa uczestników / Arm
Interwencja / Leczenie
Eksperymentalny: Nasal Cannula (NC)
Preoxygenation over 3 minutes with a nasal cannula (NC) with supplemental oxygen delivered at 15 L/min, during spontaneous breathing.
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.
Eksperymentalny: 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.
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.
Eksperymentalny: 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.
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.
Eksperymentalny: 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.
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.
Eksperymentalny: 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.
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.
Eksperymentalny: 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.
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.
Eksperymentalny: 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.
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.

Co mierzy badanie?

Podstawowe miary wyniku

Miara wyniku
Opis środka
Ramy czasowe
Difference in fraction of inspired oxygen (FiO₂) between preoxygenation devices
Ramy czasowe: 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

Miary wyników drugorzędnych

Miara wyniku
Opis środka
Ramy czasowe
Positive end-expiratory pressure (PEEP) generated during preoxygenation
Ramy czasowe: 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
Ramy czasowe: 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
Ramy czasowe: 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
Ramy czasowe: 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
Ramy czasowe: 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
Ramy czasowe: 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
Ramy czasowe: 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

Inne miary wyników

Miara wyniku
Opis środka
Ramy czasowe
Airway pressure during breath-holding maneuver
Ramy czasowe: 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)

Współpracownicy i badacze

Tutaj znajdziesz osoby i organizacje zaangażowane w to badanie.

Śledczy

  • Główny śledczy: Simon Rauch, Eurac research, Institute of mountain emergency medicine

Publikacje i pomocne linki

Osoba odpowiedzialna za wprowadzenie informacji o badaniu dobrowolnie udostępnia te publikacje. Mogą one dotyczyć wszystkiego, co jest związane z badaniem.

Daty zapisu na studia

Daty te śledzą postęp w przesyłaniu rekordów badań i podsumowań wyników do ClinicalTrials.gov. Zapisy badań i zgłoszone wyniki są przeglądane przez National Library of Medicine (NLM), aby upewnić się, że spełniają określone standardy kontroli jakości, zanim zostaną opublikowane na publicznej stronie internetowej.

Główne daty studiów

Rozpoczęcie studiów (Szacowany)

23 maja 2026

Zakończenie podstawowe (Szacowany)

30 czerwca 2026

Ukończenie studiów (Szacowany)

30 czerwca 2026

Daty rejestracji na studia

Pierwszy przesłany

26 kwietnia 2026

Pierwszy przesłany, który spełnia kryteria kontroli jakości

26 kwietnia 2026

Pierwszy wysłany (Rzeczywisty)

4 maja 2026

Aktualizacje rekordów badań

Ostatnia wysłana aktualizacja (Rzeczywisty)

8 maja 2026

Ostatnia przesłana aktualizacja, która spełniała kryteria kontroli jakości

6 maja 2026

Ostatnia weryfikacja

1 kwietnia 2026

Więcej informacji

Terminy związane z tym badaniem

Plan dla danych uczestnika indywidualnego (IPD)

Planujesz udostępniać dane poszczególnych uczestników (IPD)?

NIE

Informacje o lekach i urządzeniach, dokumenty badawcze

Bada produkt leczniczy regulowany przez amerykańską FDA

Nie

Bada produkt urządzenia regulowany przez amerykańską FDA

Nie

Te informacje zostały pobrane bezpośrednio ze strony internetowej clinicaltrials.gov bez żadnych zmian. Jeśli chcesz zmienić, usunąć lub zaktualizować dane swojego badania, skontaktuj się z register@clinicaltrials.gov. Gdy tylko zmiana zostanie wprowadzona na stronie clinicaltrials.gov, zostanie ona automatycznie zaktualizowana również na naszej stronie internetowej .

Badania kliniczne na Nasal cannula (NC)

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