Inspiratory Support Improves Preoxygenation in Healthy Subjects

The Efficacy and Tolerability of Different Levels of Inspiratory Support and PEEP During Preoxygenation. A Randomized Controlled Trial.

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00922753

Enrollment

Registered

2009-06-17

Start date

2007-02-28

Completion date

2007-09-30

Last updated

2009-06-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy

Keywords

Preoxygenation, Inspiratory, Support, Healthy, EndtidalO2

Brief summary

Preoxygenation optimizes oxygen content in the functional residual capacity (FRC). Adequate preoxygenation is defined by an expiratory oxygen fraction (FEO2) \> 90%. Inspiratory support and positive end expiratory pressure (PEEP) can create a better reservoir, improve gas exchange and shorten the time needed for adequate preoxygenation. The goal of the study is to evaluate the efficacy and tolerability of different levels of inspiratory support and positive end expiratory pressure during preoxygenation in healthy subjects.

Detailed description

We conducted a double blind prospective randomized trial on 20 healthy volunteers. Each subject went through three modes of preoxygenation in random order: normal breathing (SP), breathing under inspiratory support 4 cmH2O/PEEP 4 cmH2O (PSM-4) and inspiratory support 6 cmH2O /PEEP 4 cmH2O (PSM-6). Each mode lasted for 3 min and parameters were recorded every 10 s. We evaluated subject's tolerance, leaks and easiness of each mode of preoxygenation according to a simplified (1 to 4) scale. Two-way ANOVA was used to compare FEO2 while simple ANOVA was used for time to reach FEO2=90%.

Interventions

OTHERVS

Spontaneous breathing of 100% oxygen in a facemask for 3 minutes

OTHERAI-4/PEEP-4

Spontaneous breathing of 100% oxygen in a facemask with application of an inspiratory pressure of 4 cm H2O and a positive end-expiratory pressure of 4 cm H2O, for 3 minutes

OTHERAI-6/PEEP-4

Spontaneous breathing of 100% oxygen in a facemask with application of an inspiratory pressure of 6 cm H2O and a positive end-expiratory pressure of 4 cm H2O, for 3 minutes.

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Masking

QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

20 Years to 40 Years

Healthy volunteers

Yes

Inclusion criteria

* Healthy volunteers * Aged between 20 to 40 years

Exclusion criteria

* Body mass index \> 30 * Mustache, beard * Claustrophobia

Design outcomes

Primary

Measure	Time frame
expiratory oxygen fraction (end-tidal 02)	—

Secondary

Measure	Time frame
end-tidal CO2	—
tidal volume	—
inspiratory pressure	—
inspiratory oxygen fraction	—
leaks around the mask during preoxygenation	—
minute volume	—
endexpiratory pressure	—
subject's tolerance	—

Countries

Canada

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026