On-Demand Oxygen Delivery System Study

Study Overview
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Brief Summary
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The main goal of this study is to determine if supplemental oxygen given only when the patient is inspiring (demand delivery) is more effective than constant-flow oxygen given during all phases of the breath regardless if the patient is breathing it in. A previous study in volunteers (NCT02886312) showed that the oxygen saturation in the blood and the concentration of oxygen breathed out from the lungs (end-tidal oxygen) was higher when given in demand (inhalation only) mode. A secondary goal is to determine in patients, whether turning oxygen delivery off during expiration improves the accuracy of end-tidal CO2 (Carbon Dioxide) monitoring. This was found to be the case in the previous volunteer study. The investigators want to determine if these improvements are also observable in relatively healthy patients undergoing procedural sedation and analgesia. The efficacy of the demand mode will be determined by measuring the resulting difference in oxygen saturation and end-tidal oxygen levels. The investigators will alternate between traditional oxygen delivery (continuous flow) and demand delivery (flow only during inhalation) for two minutes in each mode after which oxygen saturation and end-tidal oxygen will be measured. End-tidal CO2 measurement will be compared with those during the brief time when O2 flow is stopped.

Official Title
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Comparison of an On-Demand Oxygen Delivery System to Continuous Flow Supplemental Oxygen in the Operating/Procedure Room

Conditions
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Oxygen Delivery, Patient Monitoring

Intervention / Treatment
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* Device: On Demand Oxygen Delivery
* Device: Traditional, Always-On, Oxygen Delivery
* Device: Oxygen Flow Stopped


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA class I-III Exclusion Criteria: Procedures scheduled for a lime less than 20 minutes Age < 18 years Baseline SpO2 (arterial oxygen saturation as measured by pulse oximetry) < 93% on room air ARDS (Acute respiratory distress syndrome), lung disease, cardiovascular disease ASA class IV or above Pregnant women.

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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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Only Arm<br>Two minutes: Intervention: Device: On Demand Oxygen Delivery 20 sec or 3 breaths, whatever comes first: Intervention: Device: Oxygen Flow Stopped Two minutes intervention: Device: Traditional, Always-On, Oxygen Delivery 20 sec or 3 breaths, whatever comes first: Intervention: Device: Oxygen Flow Stopped Repeat until the end of the surgical procedure | Device: On Demand Oxygen Delivery<br>* Supplemental oxygen flow is controlled such that it is on only during inhalation.<br>Device: Traditional, Always-On, Oxygen Delivery<br>* Supplemental oxygen flow is constantly on, irrespective of whether the patient is inhaling or exhaling.<br>Device: Oxygen Flow Stopped<br>* Supplemental oxygen flow is stopped completely for a brief period to allow undisturbed end-tidal oxygen and CO2 measurements<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| End-tidal Oxygen | Did the novel system increase end-tidal oxygen? | measured every 140 seconds minutes throughout the surgical procedure | 
| Oxygen Saturation | Did the novel system increase oxygen saturation? | measured continuously with every heart beat (i.e., approx. every 500-2000msec) throughout the surgical procedure | 
| End-tidal Carbon Dioxide | Was end-tidal carbon dioxide measured more accurately using the novel system? | measured every 140 seconds minutes throughout the surgical procedure |