Oxygen Delivery, Patient Monitoring
Conditions
Brief summary
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.
Interventions
DEVICEOn Demand Oxygen Delivery
Supplemental oxygen flow is controlled such that it is on only during inhalation.
DEVICETraditional, Always-On, Oxygen Delivery
Supplemental oxygen flow is constantly on, irrespective of whether the patient is inhaling or exhaling.
DEVICEOxygen Flow Stopped
Supplemental oxygen flow is stopped completely for a brief period to allow undisturbed end-tidal oxygen and CO2 measurements
Sponsors
University of Utah
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
SUPPORTIVE_CARE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| End-tidal Oxygen | measured every 140 seconds minutes throughout the surgical procedure | Did the novel system increase end-tidal oxygen? |
| Oxygen Saturation | measured continuously with every heart beat (i.e., approx. every 500-2000msec) throughout the surgical procedure | Did the novel system increase oxygen saturation? |
| End-tidal Carbon Dioxide | measured every 140 seconds minutes throughout the surgical procedure | Was end-tidal carbon dioxide measured more accurately using the novel system? |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORKai Kuck, Ph.D.
University of Utah Department of Anesthesiology
Outcome results
None listed