Does Supplemental Oxygen During Propofol Sedation Prevent Hypoxia?

Administration of supplemental oxygen during procedural sedation is considered standard care, largely based on the theory that increasing oxygen reserves might prevent hypoxia. In a prospective, controlled, randomized trial, investigators assessed whether administering oxygen to adult patients during procedural sedation with propofol reduces the incidence of hypoxia by 20% compared with administering room air and whether oxygen administration interferes with recognition of respiratory depression by physicians blinded to capnography results. Respiratory depression was defined as oxygen saturation ≤93%, end tidal CO₂ (ETCO₂) level ≥50 mm Hg, absolute ETCO₂ change from baseline ≥10 mm Hg, or loss of the ETCO₂ waveform.

Of 110 patients enrolled in the study, 56 received supplemental oxygen and 54 received room air at 3 L per minute via nasal cannula. Hypoxia occurred in 10 (18%) patients in the supplemental oxygen group and in 15 (28%) in the room air group; the difference of 10% was not statistically significant. Twenty-seven patients (20 supplemental oxygen, 7 room air) met ETCO₂ criteria for respiratory depression but did not become hypoxic. Physicians identified respiratory depression in 23 of the 25 patients who developed hypoxia and in only 1 of the 27 patients who met ETCO₂ criteria for respiratory depression but did not have hypoxia.