August 13, 2026

How to Master BVM Ventilation

Bag-valve-mask (BVM) ventilation is a foundational emergency care skill, and one of the most frequently performed incorrectly. Mastering it requires precise manual technique, proper airway positioning, and disciplined control of ventilation rate and volume. When done right, BVM ventilation is as effective as advanced airway placement and critical for preventing hypoxia and aspiration in cardiac arrest and respiratory emergencies.

This guide breaks down the most common mistakes, the evidence behind better technique, and what every provider should know before the next critical call.

Table of Contents

Why Bag Mask Ventilation is More Difficult Than It Looks

BVM ventilation is often underestimated as a basic skill – after all, “what’s so hard about applying a mask and squeezing the bag?” In fact, it is a complex skill requiring precise manual technique and consistent practice for proper performance. Poor technique results in ineffective ventilation with poor lung expansion, hypoxia and ultimately a failed airway.

Common Mistakes in BVM Ventilation

Ineffective ventilation often goes unrecognized for multiple reasons including lack of objective metrics when performed in the field. Additionally, providers who are experienced can often become lax or overconfident in their proficiency with ventilation when not receiving objective feedback. Experience alone does not guarantee proficiency and sometimes can worsen performance due to overconfidence and a tendency for veteran providers to ventilate too quickly and forcefully which can decrease venous return to the heart and worsen outcomes in cardiac arrest.

When BVM Ventilation Matters Most

BVM use is most critical for use in respiratory failure, respiratory arrest, and peri-intubation. In respiratory failure, the BVM is used to augment inadequate minute ventilation by assisting the patient’s spontaneous efforts as a bridge to more invasive support. During cardiac arrest, the BVM is used to maintain oxygenation and provide a means for CO2 elimination. Finally, in the peri-intubation period, BVM ventilation is used to maximize the patient’s “oxygen reservoir” in preparation for the apneic period of intubation .

Poor BVM technique can worsen intubation conditions by multiple means, including:

  • Gastric insufflation: Distending the stomach and thus increasing the risk of regurgitation and aspiration.
  • Hypoventilation: Prolonged desaturation shortens the amount of “safe” apnea time for intubation.
  • Hyperventilation: Excess ventilatory rates will increase thoracic pressure which harms venous return to the heart (and thus leads to hypotension with induction meds).

How Do You Know if Ventilation is Effective

Providers often lean heavily on visual cues such as chest rise to determine whether BVM ventilations are effective. However, this approach is highly subjective as “adequate” chest rise is impossible to quantify, particularly in obese patients, those with restrictive lung disease, or during a hectic code situation. Other signs, such as skin color, mask condensation, or auscultation are also deficient as they do not provide objective quantification of ventilation.

The gold standard continues to be End-Tidal Capnography (EtCO2). EtCO2 is superior even to pulse oximetry because it gives a real-time measurement of CO2 versus pulse oximetry which waxes and wanes over minutes at a time. EtCO2 reliably tells us about three things:

  • Metabolism: The body is producing CO2.
  • Perfusion: Blood flow is present to carry CO2 to the lungs (pertinent in a CPR situation).
  • Ventilation: The airway is patient and gas exchange is happening at the alveolar level.

For best results, the EtCO2 capnography sensor should be placed between the mask and the BVM device. This allows for the immediate measurement of CO2 as it leaves the patient’s airway. See the following image as an example of this placement:

The ETCO2 sensor fits perfectly between the bag and mask.

Three Major Causes of Poor BVM Ventilation

The vast majority of problems that clinicians encounter with BVM ventilation are caused by the same three problems: poor mask seal, improper positioning, and excessive rate and volume. All of these are caused by user error and can be improved by reviewing best practices and repetitions using proper technique.

Poor Mask Seal and Air Leak

In many courses, the “CE” technique has been historically taught where the thumb and index finger form a “C” shape to secure the mask to the patient’s mouth and nose, and the rest of the fingers pull the jaw toward the mask. This is the traditional technique taught to emergency providers, particularly when one provider administers ventilations. However, this technique often fails due to the lack of an adequate seal.

Since the CE technique only allows for hand contact on one side of the mask, uneven pressure distribution can result in an improper seal and unrecognized leaks. Additionally, provider fatigue plays a role since the CE seal is considerably demanding on hand and finger muscles. As the provider’s hand strength decreases, the mask seal will be compromised and leaks will occur.

Improper Airway Positioning

Due to the inherent difficulty and fatigue in the traditional CE mask seal, providers will often overcompensate by pushing the mask onto the face. However, this pressure inadvertently shuts the patient’s mouth and worsens airway obstruction since the nares are left as the only route of ventilation.

Additionally, with increased manual pressure on the mask, soft tissues of the pharynx collapse and occlude the glottic opening. The pressure on the jaw also forces the tongue backwards which further occludes the patient’s airway.

When the above difficulties are present, providers tend to make things worse by pressing even harder into the mask. Contrary to this approach, providers must actually work to lift the jaw upward to relax the soft tissues and the tongue, and to optimize airway space.

The Two-Handed Thenar Eminence Technique

In contrast to the CE technique for BVM ventilation, there is a superior technique available when two rescuers are present called the “Thenar Eminence” (TE) technique. In this technique, the rescuer charged with maintaining the mask seal uses both hands to place each thumb and the thenar muscles (base of thumb) on the top of each side of the mask with the other four fingers of each hand around the mandible.

This is in line with the recommendations given by the 2025 AHA Guidelines which state:

“When delivering ventilations by bag-mask device for an adult in cardiac arrest, it is reasonable for 1 rescuer to use 2 hands to open the airway and seal the mask to the face while a second rescuer squeezes the bag.”

The fingers are used to bring the jaw to the mask, while the palms and thumbs maintain a mask seal. This offers a mechanical advantage to the CE technique and allows better recognition of air leaks.

This technique has mechanical advantages over the CE technique since both hands are used to create an equal seal on both sides of the nose and mouth, and it does not tax the muscles of the hand as intensely since it utilizes a more natural grip. Due to these advantages, the Thenar Eminence technique is able to maximize ventilation effectiveness during CPR and critical respiratory situations.

Evidence Supporting the Two-Handed Technique

The two-handed technique, or “Thenar Eminence” (TE) technique, is supported by multiple studies include Gerstein (2013), who compared the effectiveness of the CE and TE technique when performed by novice clinicians and found:

“The TE facemask ventilation grip results in improved ventilation over the CE grip in the hands of novice providers.”

Both novices and veteran providers benefit from the TE technique since novices can focus on maintaining the seal with both hands and veterans benefit from improved ergonomics with the mask seal.

Excessive Rate and Tidal Volume Hyperventilation

Even when trying to be cognizant of rate and tidal volume, there can be a huge difference in the perceived and actual rate of ventilations given.

This was proven in the Milwaukee study , in which Paramedics were taught to ventilate at the appropriate rate during cardiac arrest. They retrospectively looked at the ventilation rates objectively and found the average rate was 30 breaths/min (should be 10 to 12 breaths/min)!

Hyperventilation causes dangerous physiological effects on the patient that is already in a compromised state, including decreased cardiac output (from increased intrathoracic pressure), hypocapnia (from excess removal of CO2), and gastric insufflation (discussed below). These can either hamper the success rate of resuscitative efforts or cause additional unwanted complications to the vulnerable patient.

Gastric Inflation and Aspiration Risk

Hyperventilation using a BVM can have intense deleterious effects on the unconscious patient. The 2025 AHA Guidelines note the following consequences:

  • “Excessive ventilation can cause gastric inflation, regurgitation, aspiration, and decreased cardiac output.”

This also was mentioned as far back as the 2005 AHA Guidelines :

  • “Gastric inflation often develops when ventilation is provided without an advanced airway… Air delivered with each rescue breath can enter the stomach when pressure in the esophagus exceeds the lower esophageal sphincter opening pressure. Risk of gastric inflation is increased by high proximal airway pressure and the reduced opening pressure of the lower esophageal sphincter. High pressure can be created by a short inspiratory time, large tidal volume, high peak inspiratory pressure, incomplete airway opening, and decreased lung compliance.”

Aspiration can then irritate and damage the lungs, causing reduced lung compliance.

How to Control Ventilation Rate

The primary tool for minimizing gastric inflation is to deliver breaths slowly into a properly opened airway. Most providers err on the side of ventilating too quickly, given the stress of a code situation and the hectic environment in which many codes occur. In a context in which everything is happening at a break-neck pace, it is tempting to speed up ventilations, but providers must take steps to prevent this from happening.

Some tools that come in handy for proper timing of BVM ventilations are a metronome or timing light that goes on the end of the BVM. Providers can also verbally count using the “one, one thousand… two, one thousand” method to prevent counting too quickly between breaths.

Proper Tidal Volume During BVM Ventilation

Just as hurried providers tend to deliver breaths too fast, they can also deliver too much volume to the patient in a single “squeeze”. The average volume of an adult BVM is a whopping 1600 ml while a typical single breath only requires about 500 ml depending on the person’s size. Thus, it’s recommended that only 1/3 of the bag be compressed to give an adequate tidal volume without overinflating the lungs or forcing air into other spaces such as the esophagus and stomach.

BVM Ventilation During Cardiac Arrest

In 2-rescuer CPR with a 30:2 ratio of compressions to breaths, the ventilatory breaths should be performed more rapidly. Per the 2025 AHA Guidelines, breaths may be given over 1 second each during the pause between sets of compressions. This equals about 5 seconds of CPR stoppage (2 seconds for each inspiration/expiration pattern, repeated once), after which compressions should be restarted immediately with minimal interruption.

One danger here is that provider will often start the 2nd breath in the set before the “exhale” from the 1st breath is complete, trapping CO2 and increasing intrathoracic pressure. To prevent this, allow the BVM bag to fully recoil after each ventilation “squeeze”.

Key Takeaways for Effective BVM Ventilation

In summary, BVM ventilation is often underestimated as a “basic” skill while mistakes can go unrecognized by providers. Remember these best practices:

  • EtCO2 is the best indicator of proper ventilation.
  • Poor mask seal can be corrected using two hands with the “Thenar Eminence” technique.
  • Hyperventilation should be corrected with adjunctive measures such as a metronome.
  • Compress only 1/3rd of the BVM bag with each breath.
  • Allow full release of the BVM when giving breaths in a 30:2 ratio CPR.

BVM mastery is essential for survival, often with more importance than an advanced airway in critical situations. BVM proficiency can be achieved via deliberate practice with instructive feedback. Engagement with both BLS Training and ACL Training courses is the most efficient way to bolster these skills. Consider building your foundation in these skills by registering for the first time or for recertification today!

References

Aufderheide TP, Lurie KG. Death by hyperventilation: a common and life-threatening problem during cardiopulmonary resuscitation. Crit Care Med. 2004;32(9 Suppl):S345-S351. doi:10.1097/01.ccm.0000134335.46859.09

ECC Committee, Subcommittees and Task Forces of the American Heart Association. 2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2005;112(24 Suppl):IV1-IV203. doi:10.1161/CIRCULATIONAHA.105.166550

Gerstein NS, Carey MC, Braude DA, et al. Efficacy of facemask ventilation techniques in novice providers. J Clin Anesth. 2013;25(3):193-197. doi:10.1016/j.jclinane.2012.10.009

Kim TY, Kim S, Han SI, et al. Gastric Inflation in Prehospital Cardiopulmonary Resuscitation: Aspiration Pneumonia and Resuscitation Outcomes. Rev Cardiovasc Med. 2023;24(7):198. Published 2023 Jul 12. doi:10.31083/j.rcm2407198

Panchal AR, Berg KM, Hirsch KG, et al. Part 3: Adult basic and advanced life support: 2020 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2020;142(16_suppl_2):S366-S468. doi:10.1161/CIR.0000000000000916

Panchal AR, Berg KM, Kudenchuk PJ, et al. Part 7: Adult basic life support: 2025 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2025;152(16_suppl_1). doi:10.1161/CIR.0000000000001298

Panchal AR, Berg KM, Kudenchuk PJ, et al. Part 9: Adult advanced life support: 2025 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2025;152(16_suppl_1). doi:10.1161/CIR.0000000000001300

Soleimanpour M, Rahmani F, Morteza Bagi HR, et al. Comparison of Three Techniques on Facility of Bag-Mask Ventilation: Thenar Eminence, E-O and E-C. Anesth Pain Med. 2018;8(4):e74226. Published 2018 Aug 11. doi:10.5812/aapm.74226

About Author

Floyd Miracle

Floyd Miracle (@fmiracle36) is Associate Editor of ACLSMedicalTraining.com (@ACLSMedTraining) and Paramedic and preceptor in Richmond Kentucky.

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