Pre-oxygenation With Real Time End-tidal Oxygen Measurements Versus Single Breath Measurements

Study Overview
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Brief Summary
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This study examines the performance of a nasal cannula end-tidal oxygen (EtO2) measurement as compared to the gold standard of single breath end-tidal oxygen measurements in healthy volunteers. The purpose of this study is to examine the ability of each sensor to predict oxygen levels in real time.

Detailed Description
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Patients in the Emergency Department (ED) undergoing Rapid Sequence Intubation (RSI) are at risk for serious morbidity and mortality. In order to provide oxygen during the apneic period, it is common practice to provide pre-oxygenation prior to the start of the procedure with high flows of oxygen. Techniques commonly employed to pre-oxygenate ED patients undergoing RSI include high flow oxygen via a non-rebreather mask (NRBM), a self-inflating bag-valve mask (BVM), or non-invasive ventilation (NIV). However, there are currently no studies that explore how to assess the quality of a patient's pre-oxygenation in real time prior to intubation. Several recent studies that have assessed the use of single breath end-tidal oxygen to assess the effectiveness of various oxygenation strategies. Typically, healthy volunteers are placed on 2 to 3 minutes of a certain pre-oxygenation strategy followed by exhalation of a single breath into an end-tidal oxygen sensor. Higher end-tidal oxygen measurements are used as a marker for pre-oxygenation with higher percentages indicating more complete pre-oxygenation. A goal EtO2 reading of 90% is typically used to indicate maximal pre-oxygenation. However, this method of assessing pre-oxygenation would be impractical in actual ED patients who are critically ill and may not be able to fully participate in such a measurement. In addition, discontinuing a pre-oxygenation method to obtain a single breath EtO2 reading would be unethical as it would interfere with proper pre-oxygenation in a critically ill patient. A better method would be to examine end-tidal oxygen measurements from patients in real-time as they are being pre-oxygenated. This study will examine the use of a real time nasal cannula EtO2 sensor as compared to the gold standard of a single breath exhalation into a static sensor. Healthy participants will be randomly assigned to use the non-rebreather mask or the non-invasive ventilator. A baseline EtO2 measurement will be obtained with the nasal cannula EtO2 sensor then the mask the participant was randomized to use will be placed over the nasal cannula EtO2 sensor and oxygenation trials will begin. At the end of each trial a single breath end-tidal oxygen measurement will be obtained.

Official Title
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Real Time Assessment of Pre-oxygenation Utilizing End-tidal Oxygen Measurements Versus Single Breath End-Tidal Oxygen Measurements in Healthy Volunteers

Conditions
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Rapid Sequence Intubation

Intervention / Treatment
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* Device: Non-rebreather mask (NRBM)
* Device: Non-invasive ventilator mask (NIV)
* Device: Nasal cannula EtO2 sensor
* Drug: Oxygen (NRBM)
* Drug: Oxygen (NIV)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adults 18 years of age and older who are able to consent on their own without a legal representative Self-identified as being in good health Grossly normal dentition as judged by study investigators No history of severe pulmonary disease or asthma that requires daily use of an inhaler Females participants self-report to not be pregnant at time of study enrollment Study participants will be recruited from within the Department of Emergency Medicine at Grady Memorial Hospital and will include nursing staff, paramedical staff, medical students, residents, and attending physicians Exclusion Criteria: Participant does not agree to study enrollment Participant cannot tolerate the entire course of non-invasive ventilation required to complete the study Participant does not agree to the video recording of the oxygen monitor to ensure proper data transcription

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Non-rebreather mask (NRBM)<br>Prior to the start of the study procedure, a nasal cannula end-tidal oxygen (EtO2) sensor will be placed on the participant's face with the non-rebreather mask (NRBM) overlying the sensor. The participants will be randomized to the order of their treatment sequence as follows: oxygen at 15 liters per minute (LPM) for 3 minutes, at 35 LPM for 3 minutes, or at flush rate (55 LPM) for 3 minutes. The maximal reading at the end of this will be recorded, then the study subjects will be allowed to rest until their EtO2 returns to their baseline. They will then be placed back on NRBM at flush rate, allowed to rise to the maximal reading of the previous step, then do a single breath exhaled EtO2 measurement. | Device: Non-rebreather mask (NRBM)<br>* The non-rebreather mask (NRBM) will be used to assist in the delivery of oxygen. Participants will be placed on NRBM at different flow rates (15 LPM, 35 LPM, or Flush rate at 55 LPM).<br>Device: Nasal cannula EtO2 sensor<br>* The nasal cannula EtO2 sensor will be placed on the participant's face under the mask to detect the EtO2 levels.<br>Drug: Oxygen (NRBM)<br>* Oxygen will be delivered via the NRBM. Participants will receive oxygen at different flow rates (15 LPM, 35 LPM, or flush rate at 55 LPM).<br>|
| Active Comparator: Non-invasive ventilator mask (NIV)<br>Prior to the start of the study procedure, a nasal cannula end-tidal oxygen (EtO2) sensor will be placed on the participant's face with the non-invasive ventilator mask (NIV) overlying the sensor. Participants will be randomized to the order of their treatment sequence as follows: NIV at 50% fraction of inspired oxygen (FiO2) for 3 minutes, NIV at 75% FiO2 for 3 minutes, NIV at 100% FiO2 for 3 minutes, the maximal reading at the end of this trial will be recorded. The study subjects will be allowed to rest until their EtO2 returns to their baseline, then they will be placed back on NIV at 100% FiO2, allowed to rise to the maximal reading of the previous step, then do a single breath exhaled EtO2 measurement. | Device: Non-invasive ventilator mask (NIV)<br>* The NIV is a non-invasive face (nasal) mask for oxygen delivery. Participants will receive oxygen at 50% FiO2 for 3 minutes, 75% FiO2 for 3 minutes or 100% FiO2 for 3 minutes each.<br>Device: Nasal cannula EtO2 sensor<br>* The nasal cannula EtO2 sensor will be placed on the participant's face under the mask to detect the EtO2 levels.<br>Drug: Oxygen (NIV)<br>* Oxygen will be delivered via the NIV mask. Participants will receive oxygen at 50% FiO2, 75% FiO2 or 100% FiO2 for 3 minutes each.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Degree of correlation between real time and single breath EtO2 measurements | The degree of correlation between real time EtO2 measurements and a single breath end-tidal oxygen measurement as measured by the k correlation coefficient will be done at the end of 3 minutes. Correlation coefficients are expressed as values between +1 and -1 and is a statistical measure of the degree to which changes to the value of one variable predict change to the value of the other. | At 3 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of EtO2 between the nasal cannula and single breath sensors | The correlation of EtO2 between the nasal cannula sensor and the single breath sensor once stabilized at maximal readings as measured by the k correlation coefficient will be done at the end of 3 minutes. Correlation coefficients are expressed as values between +1 and -1 and is a statistical measure of the degree to which changes to the value of one variable predict change to the value of the other. | At 3 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Intubation, Emergency department, Pre-oxygenation