Department of Emergency Medical Technology, Daejeon University, 62 Daehak-ro, Dong-gu, Daejeon, 34520, Republic of Korea.
Department of Emergency Medical Technology, Kyungil University, 50, Gamasil-gil, Hayang-eup, Gyeongsan-si, Gyeongbuk, 38428, Republic of Korea.
BMC Emerg Med. 2021 May 1;21(1):57. doi: 10.1186/s12873-021-00451-1.
For adequate ventilation during bag-valve-mask ventilation, rescuers should ensure a proper mask seal using the one-handed or two-handed technique. Little is known about the magnitude of sealing forces of a bag-valve-mask needed for adequate ventilation. This study aimed to explore the effect of the 4-point sealing forces of a bag-valve-mask on tidal volume while using the one-handed technique, focusing on the moderating effect of C length (the distance from the thumb to the index finger in the C shape of the one-hand EC grip).
A prospective, descriptive simulation study was conducted. A convenience sample of 125 undergraduate paramedic students from two universities was recruited. A self-reported questionnaire was used to collect subjective variables. Tidal volumes, 4-point sealing forces of the mask, peak pressure, and C length of the C shape in the one-hand EC grip were measured using the mechanical lung model under a simulated adult respiratory arrest. Hierarchical regression analysis was used to determine the moderating effect of C length on tidal volume in bag-valve-mask ventilation.
The average C length, peak pressure, and tidal volume were 7.54 (± 1.85) cm, 11.62 (± 5.40) cmHO, and 321.66 (± 135.18) mL, respectively. The average range of the 4-point sealing forces was 0.03-0.69 N. The apex sealing force was the weakest among the 4-point sealing forces. Hierarchical regression analysis demonstrated that tidal volume accounted for 62.7% of the variance by C length, peak pressure, and apex sealing force during bag-valve-mask ventilation (F = 9.676, p < 0.001). C length moderated the effect of the apex sealing force and peak pressure on the tidal volume, meaning the higher the peak pressure and apex sealing force, the more the tidal volume and the longer the C length.
This first simulation study measuring the 4-point sealing forces during bag-valve-mask ventilation provides effective advice that can be adopted in clinical practice without side effects and underpins the importance of continuous retraining and assessment focused on individual physical characteristics, such as C length and bag-valve-mask sealing forces.
为了在进行球囊面罩通气时获得足够的通气，救援人员应使用单手或双手技术确保面罩密封良好。目前对于实现充分通气所需的球囊面罩的密封力大小知之甚少。本研究旨在探讨单手技术中球囊面罩的四点密封力对潮气量的影响，并重点关注 C 长度（单手 EC 握法中拇指到食指的 C 形距离）的调节作用。
进行了一项前瞻性描述性模拟研究。从两所大学招募了 125 名本科急救医学专业学生作为方便样本。使用自我报告问卷收集主观变量。在模拟成人呼吸暂停的情况下，使用机械肺模型测量潮气量、面罩的四点密封力、峰压和单手 EC 握法中 C 形的 C 长度。使用分层回归分析确定 C 长度对球囊面罩通气中潮气量的调节作用。
平均 C 长度、峰压和潮气量分别为 7.54（±1.85）cm、11.62（±5.40）cmH₂O 和 321.66（±135.18）mL。四点密封力的平均范围为 0.03-0.69 N。四点密封力中顶点密封力最弱。分层回归分析表明，在球囊面罩通气期间，潮气量可由 C 长度、峰压和顶点密封力解释 62.7%的变异性（F=9.676，p<0.001）。C 长度调节了顶点密封力和峰压对潮气量的影响，即峰压和顶点密封力越高，潮气量越大，C 长度越长。
这是第一项测量球囊面罩通气期间四点密封力的模拟研究，为临床实践提供了无副作用的有效建议，并强调了持续培训和评估的重要性，重点是个人身体特征，如 C 长度和球囊面罩密封力。
