protocolSection identificationModule nctId: NCT06370689, orgStudyIdInfo id: PRE-OX, briefTitle: Comparison of Three Pre-oxygenation Strategies, statusModule overallStatus: NOT_YET_RECRUITING, startDateStruct date: 2024-05-23, primaryCompletionDateStruct date: 2024-12-31, completionDateStruct date: 2025-07-30, studyFirstPostDateStruct date: 2024-04-17, lastUpdatePostDateStruct date: 2024-04-17, sponsorCollaboratorsModule leadSponsor name: Institute of Mountain Emergency Medicine, class: OTHER, descriptionModule briefSummary: Study objective: Comparing the efficacy of three different preoxygenation strategies, i.e. non-rebreather face mask (NRM), bag-valve-mask (BVM) with and BVM without additional positive end-expiratory pressure (PEEP) in three subgroups of spontaneously breathing volunteers.Study endpointsPrimary Endpoint:The time taken from the start of preoxygenation until reaching an expiratory oxygen concentration (FeO2) of ≥ 90% or a maximum preoxygenation time of 3 min.Secondary endpoints:* Changes in regional ventilation within the posterior lung regions from baseline to the time when FeO2≥ 90% is achieved, assessed using electrical impedance tomography (EIT)* Difference in Oxygen Reserve Index (ORi) when FeO2≥ 90% is achievedNumber of participants 15 participants per subgroup, i.e. 45 participants in total.Inclusion criteria* Normal-weight adults (body mass index, BMI 18.5-24.9 kg/m2) with an "American Society of Anesthesiologists Physical Status Classification System (ASA) " score of I or II* Adults with a BMI 25-39.9 kg/m2 with and ASA score \<3* Healthy (ASA I) children aged 6-12 years Exclusion criteria ASA 3, Age \< 6 and age 12-18, pregnant women, missing informed consent, signs and symptoms of an acute respiratory illness on the study day.After informed consent and a medical check-up, baseline measurements will be done for 10 minutes (peripheral oxygen saturation SpO2, ORI, regional ventilation). Then the participants will undergo 3 different preoxygenation sessions with the 3 interfaces (i.e. non-rebreather facemask with reservoir and a bag-valve-mask with and without PEEP) in a randomized order and a 20 min washout between the sessions. Each preoxygenation session is conducted in a supine position and will be proceeded until the measured FeO2 (end expiratory O2 fraction) reaches 90% or up to a maximum time of 3 min. Afterwards 10 min of SpO2, ORI and regional ventilation measurements will follow., conditionsModule conditions: Emergencies, conditions: Anesthesia, designModule studyType: INTERVENTIONAL, phases: NA, designInfo allocation: RANDOMIZED, interventionModel: CROSSOVER, primaryPurpose: OTHER, maskingInfo masking: NONE, enrollmentInfo count: 45, type: ESTIMATED, armsInterventionsModule interventions name: Preoxygenation, outcomesModule primaryOutcomes measure: Difference in Oxygen Reserve index (ORi) after 3 minutes of preoxygenation, secondaryOutcomes measure: Difference in expiratory oxygen concentration (FeO2) after 3 minutes of preoxygenation, secondaryOutcomes measure: Time to Oxygen Reserve index (ORi) = 1.0, eligibilityModule sex: ALL, minimumAge: 6 Years, stdAges: CHILD, stdAges: ADULT, stdAges: OLDER_ADULT, contactsLocationsModule, hasResults: False