Preoxygenation With and Without Positive End-Expiratory Pressure in Lung-Healthy Volunteers
Authors: Giulia Roveri, Anna Camporesi, Alex Hofer, Simon Kahlen, Franziska Breidt, Simon Rauch
Journal: JAMA Network Open (2025)

Importance Optimal preoxygenation is critical in emergency medicine to prevent desaturation during airway management, especially in high-risk populations. Identifying the most effective preoxygenation device across diverse patient groups remains a clinical priority. Objective To compare the efficacy of 3 preoxygenation devices—nonrebreather mask (NRM), bag-valve mask (BVM), and BVM with positive end-expiratory pressure (BVM plus PEEP)—in lung-healthy volunteers. Design, Setting, and Participants This crossover randomized clinical trial was conducted from May 26 to 31, 2024, at Eurac Research, Bolzano, Italy. Volunteer participants included lung-healthy adults with normal weight (NM), adults with overweight or obesity (OW-OB), and children aged 6 to 12 years. Exposures Preoxygenation using each device (NRM, BVM, BVM plus PEEP) with 15 L/min of oxygen for a duration of 3 minutes in a randomized order. Main Outcomes and Measures The primary outcome was expiratory oxygen concentration (Fe o 2 ) at the end of preoxygenation. Secondary outcomes included ventilation in dependent lung regions assessed using electrical impedance tomography, noninvasive continuous monitoring of oxygenation status (oxygenation reserve index [ORI]) at the end of preoxygenation, and the time taken for ORI to return to baseline values. Results The study included 53 participants, 39 male (74%) and 14 female (26%), of whom 16 were adults with NW (mean [SD] age, 36 [11] years), 18 were adults with OW-OB (mean [SD] age, 45 [11] years), and 19 were children (mean [SD] age, 8 [3] years). Mean (SD) Fe o 2 at the end of preoxygenation was higher with BVM and BVM plus PEEP compared with NRM in adults with NW (72.1% [5.9%] and 75.6% [4.3%], respectively, vs 52.5% [6.1%]; P &amp;amp;lt; .001), adults with OW-OB (65.8% [10.4%] and 73.0% [6.4%], respectively, vs 51.9% [6.1%]; P &amp;amp;lt; .001), and children (64.6% [13.4%] and 67.5% [10.2%], respectively, vs 38.5% [7.5%]; P &amp;amp;lt; .001). Ventilation in dependent lung regions was higher with BVM plus PEEP than NRM in adults with NW (BVM plus PEEP, 51.9 [9.3] vs NRM, 47.0 [5.7]; P = .03) and children (BVM plus PEEP, 53.0 [7.3] vs NRM, 47.7 [7.0]; P = .002). ORI at the end of preoxygenation was higher with BVM plus PEEP than with NRM in adults with OW-OB (BVM plus PEEP, 0.79 [0.13] vs NRM, 0.73 [0.13]; P &amp;amp;lt; .001). Additionally, the mean (SE) time for ORI to return to baseline was longer with BVM plus PEEP compared with NRM in both adults with OW-OB (BVM plus PEEP, 196 [74] seconds vs NRM, 158 [53] seconds; P = .01) and children (BVM plus PEEP, 115 [59] seconds vs NRM, 62 [36] seconds; P &amp;amp;lt; .001). Conclusions and Relevance In this crossover randomized clinical trial, preoxygenation with PEEP was more effective than preoxygenation without PEEP, resulting in higher Fe o 2 values and improved ventilation in dependent lung regions. These findings suggest that BVM plus PEEP should be prioritized for preoxygenation in emergency settings. Trial Registration ClinicalTrials.gov Identifier: NCT06370689