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.
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
End-tidal Oxygen
Timeframe: measured every 140 seconds minutes throughout the surgical procedure
Oxygen Saturation
Timeframe: measured continuously with every heart beat (i.e., approx. every 500-2000msec) throughout the surgical procedure
End-tidal Carbon Dioxide
Timeframe: measured every 140 seconds minutes throughout the surgical procedure