Effect of Proximal Oxygen Adding to a Bag Valve Mask with a Mechanical Filter in Healthy Volunteers: A Randomized Crossover Trial
จิตติยา วั ชโรทยางกูร, Gorranit Thummata, Kittiya Srisitpisarn, ธนิต วีรังคบุตร, ธัญลักษณ์ ธรรมจำรัสศรี*
Department of Anesthesiology, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand; Phone: +66-81-9562004; Email: [email protected]
Background: Preoxygenation using a bag valve mask (BVM) with a filter is recommended to reduce the risk of viral transmission. Preoxygenation in hypoxaemic patients may require a positive end-expiratory pressure (PEEP) valve. Applying a filter to a BVM with or without a PEEP valve can increase resistance and work of breathing.
Objective: To evaluate the efficacy of proximal oxygen added to BVM with mechanical filter in healthy volunteers.
Materials and Methods: The present study was a crossover trial that randomized 48 volunteers to receive four preoxygenation techniques: BVM with a filter as group F, BVM with a filter and proximal oxygen as group FO, BVM with a filter and PEEP valve as group FP, and BVM with a filter, PEEP valve, and proximal oxygen as group FPO. Fraction of expired oxygen (FEO) and continuous positive airway pressure (CPAP) were measured. Comfort was assessed using a numerical rating scale (NRS). The primary outcome was FEO₂ at five minutes.
Results: Data from 46 volunteers were analyzed. Adding oxygen proximal to the filter in the FO group increased FEO at five minutes by 7.07% (95% CI 4.87 to 9.26) and decreased the time to reach FEO 90% by 301.74 seconds (95% CI 282.82 to 320.66) compared with the times in group F. Similarly, supplemental proximal oxygen including a PEEP valve increased FEO₂ at five minutes by 6.07% (95% CI 3.87 to 8.26) and decreased the time to reach FEO₂ 90% by 242.13 seconds (95% CI 223.21 to 261.05). CPAP was 2.27, 3.61, 11.65, and 13.14 mmHg in group
F, FO, FP, and FPO, respectively. The NRS score was 6.51 and 6.07 in groups
F and FO, and 3.15 and 3.70 in groups FP and FPO, respectively.
Conclusion: Adding proximal oxygen to a BVM with a filter improved the efficacy of preoxygenation.
วารสารจดหมายเหตุทางการแพทย์ ปี 2566, January ปีที่: 106 ฉบับที่ 1 หน้า 49-55
"Bag valve mask, Efficacy of preoxygenation, Healthy volunteers, Mechanical filter, Positive end-expiratory pressure, Positive endexpiratory pressure valve"