The Airway Pressures During Bag-Valve-Mask Ventilation

The Airway Pressures During Bag-Valve-Mask Ventilation: A Randomized Crossover Trial

Background and Objective Bag-valve-mask (BVM) ventilation is commonly used in emergency airway management, but the positive pressure generated may increase aspiration risk. This prospective, randomized, simulation-based manikin study aimed to assess how airway pressures change during BVM ventilation using different techniques and neck mobility scenarios.

Methods The study was conducted in a tertiary university hospital between July 15 and August 15, 2024. Emergency medicine residents (PGY-1 to PGY-4) performed ten ventilations using one-hand, two-hand CE, and modified two-hand TE techniques on a manikin under normal and restricted neck mobility. Airway pressures were measured with a real-time pressure sensor. The primary outcome was peak airway pressure; the secondary was the number of ventilations exceeding 20 cmH₂O. All data were automatically recorded, and analyses were performed using SPSS 16.0 with p < 0.05 considered significant.

Study Overview

• Status: Completed
• Conditions: Emergency Airway Management; Gastric Inflation Risk During Bag-Valve-Mask Ventilation; Breathing Emergency
• Intervention / Treatment: Other: Two Handed CE Technique; Other: Two Handed TE Technique; Other: One Handed Technique

Detailed Description

Introduction:

Emergency department (ED) patients are considered to have an elevated risk of gastric distention and aspiration of gastric contents, making rapid sequence induction (RSI) the preferred intubation procedure. Pre-oxygenation is likely the most critical step in RSI, as it extends the duration of safe apnea time, providing the operator with more time for the intubation process. Although a facemask with a high FiO2 oxygen reservoir is recommended for pre-oxygenation, bag-valve-mask (BVM) ventilation is frequently used in emergency airway management.

Since its development during the polio epidemic in 1953, the BVM has been used for oxygenation and ventilation of critically ill patients. However, the positive pressure generated by the BVM can increase the risk of regurgitation and aspiration of gastric contents into the lungs. Excessive volumes and flow generated with the BVM can not only lead to gastric distention but also increase intrathoracic pressures, potentially causing negative cardiovascular effects.

The aim of this randomized crossover manikin study is to investigate how airway pressures change during ventilation with a BVM using different scenarios and techniques.

Methods:

This is a randomized crossover trial performed in the simulation lab of a tertiary care facility between 15.07.2024 to 15.08.2024. The ethical committee of XXX approved the study and informed consent was obtained from the participants. The participants were emergency medicine residents ranging from postgraduate year 1 (PGY) to PGY4.

In this study, airway pressures during BVM ventilation were continuously recorded using a calibrated pressure sensor placed between the facemask and the bag. All participants were requested to ventilate the Resusci Anne QCPR airway mannequin (Laerdal Medical, Stavanger, Norway) in a randomized manner using one-hand, two-hand (CE method), and modified two-hand (TE method) techniques, while the airway pressures were measured. Two different scenarios were applied to simulate normal and difficult airways while ventilating the airway mannequin. For the difficult airway scenario, a cervical collar was applied to the airway mannequin. To reduce potential bias, the purpose of the study was not explained to the participants Each participant was asked to provide a sufficient amount of air with the BVM to raise the mannequin's chest and to repeat these 10 times in a randomized order. All the pressure values measured during ventilation were recorded as cmH2O. The highest-pressure value measured during ventilations, as well as the number of ventilations during which the pressure exceeded 20 cmH2O, were recorded.

The differences in the pressure values measured using different hand techniques in normal and difficult airway scenarios were evaluated. Additionally, it was assessed which scenario and technique resulted in pressures exceeding 20 cmH2O, based on the theoretical assumption that pressures above this value would open the lower esophageal sphincter and inflate the stomach with air. This assumption was based on previous studies indicating that lower esophageal sphincter pressure is typically exceeded, and gastric inflation begins, when airway pressure surpasses 20 cmH₂O.

Statistical analysis:

The study data were analyzed using the SPSS software version 16.0 for Windows (SPSS Inc., Chicago, IL, USA). Demographic and baseline characteristics were summarized as a mean ± standard deviation for continuous variables and as a percentage of the group for categorical variables. Non-normally distributed data are presented as medians (interquartile range). For each scenario and technique, the participant was considered the unit of analysis. For every participant, the highest pressure value among the 10 ventilations and whether ≥5 of 10 ventilations exceeded 20 cmH2O were used in the analyses The chi-square test was used to compare the ventilations exceeding the 20 cmH2O pressure value with PGY levels. P < 0.05 was accepted as statistically significant.

• Study Type: Interventional
• Enrollment (Actual): 46
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Antalya, Turkey (Türkiye), 07059
    • Akdeniz University Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 18 years or older.
• Medical residents (Post-graduate years 1-4) or practicing emergency medicine physicians.
• Ability and willingness to provide informed consent to participate in the simulation.
• Experience with basic airway management and BVM ventilation in a clinical setting.

Exclusion Criteria:

• Lack of Experience:
• Any musculoskeletal or neurological condition that would prevent the participant from performing manual BVM maneuvers effectively.
• Refusal to Participate: Inability to provide informed consent.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: PGY juniors (under 2 yrs); Residents who have been working as assistants for less than two years	Other: Two Handed CE Technique; Describes the CE hand-holding position during the balloon mask ventilation.; Other: Two Handed TE Technique; Describes the TE hand-holding position during the balloon mask ventilation.; Other: One Handed Technique; Describes the One hand-holding position during the balloon mask ventilation.
Other: PGY Senior ( above 2 years); Residents who have been working as assistants for more than two years.	Other: Two Handed CE Technique; Describes the CE hand-holding position during the balloon mask ventilation.; Other: Two Handed TE Technique; Describes the TE hand-holding position during the balloon mask ventilation.; Other: One Handed Technique; Describes the One hand-holding position during the balloon mask ventilation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of airway pressure exceeding 20 cmH2O	The frequency of breaths delivered with a peak airway pressure greater than 20 cmH2O (the threshold for gastric inflation risk) during Bag-Valve-Mask (BVM) ventilation.	During the ventilation procedure (a continuous 10-breath sequence per technique/scenario

Collaborators and Investigators

• Sponsor: Akdeniz University Hospital

Publications and helpful links

General Publications

• 1- Weingart SD, Levitan RM. Preoxygenation and prevention of desaturation during emergency airway management. Ann Emerg Med. 2012 Mar;59(3):165-75.e1. doi: 10.1016/j.annemergmed.2011.10.002. 2- Lee CP, Yip YY. Understanding your bag-valve-mask resuscitator. BJA Educ. 2023 Jun;23(6):208-211. doi: 10.1016/j.bjae.2023.03.003. 3- Lawes EG, Campbell I, Mercer D. Inflation pressure, gastric insufflation, and rapid sequence induction. Br J Anaesth. 1987 Mar;59(3):315-8. doi: 10.1093/bja/59.3.315. 4- Bowman FP, Menegazzi JJ, Check BD, Duckett TM. Lower esophageal sphincter pressure during prolonged cardiac arrest and resuscitation. Ann Emerg Med. 1995 Aug;26(2):216-9. doi: 10.1016/s0196-0644(95)70154-0. 5- von Goedecke A, Wagner-Berger HG, Stadlbauer KH, Krismer AC, Jakubaszko J, Bratschke C, Wenzel V, Keller C. Effects of decreasing peak flow rate on stomach inflation during bag-valve-mask ventilation. Resuscitation. 2004 Nov;63(2):131-6. doi: 10.1016/j.resuscitation.2004.04.012.

Study record dates

Study Major Dates

• Study Start (Actual): July 15, 2024
• Primary Completion (Actual): August 15, 2024
• Study Completion (Actual): August 15, 2024

Study Registration Dates

• First Submitted: April 30, 2026
• First Submitted That Met QC Criteria: May 13, 2026
• First Posted (Actual): May 18, 2026

Study Record Updates

• Last Update Posted (Actual): May 18, 2026
• Last Update Submitted That Met QC Criteria: May 13, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: lower esophageal sphincter; gastric insufflation; Bag-valve mask; Hand-grip techniques
• Other Study ID Numbers: AkdenizUH

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Anonymized data can be shared if deemed appropriate when requested.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No