Supplemental oxygen compromises the use of pulse oximetry for detection of apnea and hypoventilation during sedation in simulated pediatric patients

OBJECTIVE. The goal was to assess the time to recognition of apnea in a simulated pediatric sedation scenario, with and without supplemental oxygen. METHODS. A pediatric human patient simulator mannequin was used to simulate apnea in a 6-year-old patient who received sedation for resetting of a fractured leg. Thirty pediatricians participating in a credentialing course for sedation were randomly assigned to 2 groups. Those in group 1 (N = 15) used supplemental oxygen, and those in group 2 (N = 15) did not use supplemental oxygen. A third group (N = 10), consisting of anesthesiology residents (postgraduate years 2 and 3 equivalent), performed the scenario with oxygen supplementation, to ensure validity and reliability of the simulation. The time interval from simulated apnea to bag-mask ventilation was recorded. Oxygen saturation and PaCO2 values were recorded. All recorded variables and measurements were compared between the groups. RESULTS. The time interval for bag-mask ventilation to occur in group 1 (oxygen supplementation) was significantly longer than that in group 2 (without oxygen supplementation) (173 +/- 130 and 83 +/- 42 seconds, respectively). The time interval for bag-mask ventilation to occur was shorter in group 3 (anesthesiology residents) (24 +/- 6 seconds). PaCO2 reached a higher level in group 1 (75 +/- 26 mm Hg), compared with groups 2 and 3 (48 +/- 10 and 42 +/- 3 mm Hg, respectively). There was no significant difference between the groups in oxygen saturation values at the time of clinical detection of apnea (93 +/- 5%, 88 +/- 5%, and 94 +/- 7%, respectively). CONCLUSIONS. Hypoventilation and apnea are detected more quickly when patients undergoing sedation breathe only air. Supplemental oxygen not only does not prevent oxygen desaturation but also delays the recognition of apnea.