Bag mask ventilation (BMV) is a method for providing a person with immediate ventilation in an emergency. BMV involves a medical professional manually pumping oxygen into a person’s lungs using a self-inflating bag to simulate breathing.

Certain health conditions and accidents can cause a person to have breathing difficulties. BMV uses bag valve masks, or Ambu bags, to supply a person with oxygen.

A bag valve mask is a handheld tool that a medical professional can use to pump oxygen into a person’s lungs.

This article details BMV, including how it works, step-by-step instructions, effectiveness, and possible risks.

A bag mask device to deliver breaths.Share on Pinterest
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The equipment used for BMV includes:

  • self-inflating bag
  • mask that covers a person’s nose and mouth
  • oxygen source
  • oxygen tubing
  • positive end-expiratory pressure (PEEP) valve, which helps maintain pressure in the lower airways during exhalation
  • tubes to hold the airways open

The self-inflating bag is attached to a valve and then to a soft face mask. The other end of the self-inflating bag is attached to a tank containing 100% oxygen.

A medical professional then places the face mask over a person’s nose and mouth, then manually squeezes the self-inflating bag. Squeezing the bag pushes oxygen into the person’s lungs, which replicates the action of breathing.

A medical professional can attach a PEEP valve to the bag valve mask to help maintain pressure inside the lungs. This can help prevent damage to the delicate sacs of air on the lungs, called alveoli.

A medical professional will perform the following steps:

  1. Stand behind the person and tilt their chin slightly upward to open their airway.
  2. Insert a tube into the person’s mouth to prevent the tongue from covering the airway. They may insert a tube into the nose if the throat is blocked.
  3. Place the mask over the person’s nose and mouth, and apply pressure to the mask with one hand to keep the seal tight.
  4. Before attaching the oxygen, squeeze the self-inflating bag, allowing air to flow into the person’s lungs. Empty the entire bag over 1⁠–2 seconds and then release it. Releasing the bag allows it to refill.
  5. Continue providing ventilation for 30 seconds before attaching the oxygen tank.
  6. Attach the oxygen, and supply the person with 15 liters of oxygen per minute.

If there are two medical professionals, one will hold the mask in place while the other squeezes the self-inflating bag.

The method is the same in adults and children. However, they will use smaller bag valve masks for children.

Medical professionals use BMV in emergencies to provide a rapid supply of oxygen. A person may need assistance breathing if they are experiencing:

Some people may also require BMV before certain scheduled surgeries.

Without an adequate amount of oxygen, a person can develop hypoxia. Hypoxia is a condition where a person does not have enough oxygen in their body tissues.

It can be mild or severe, causing symptoms such as:

Hypoxia can also lead to coma or death.

Research suggests that BMV can be a successful ventilation technique when used correctly.

A study from 2020 found that bag valve mask-only ventilation was associated with improved cardiac arrest episodes that occurred outside a hospital.

Additionally, research from 2019 found that critically ill people receiving BMV alongside tracheal intubation had higher oxygen saturation levels and lower rates of severely low oxygen levels.

Affecting factors

The success of BMV ventilation can depend on certain factors, such as:

  • the person’s airway
  • a tight seal on the face mask
  • proper ventilation technique
  • using a PEEP value when required

A medical professional must ensure that a person is in the correct position before beginning BMV. Certain factors can make BMV more difficult for a healthcare professional.

These factors include people who:

  • have obesity
  • are older adults
  • have no teeth
  • have beards
  • are snoring
  • are stiff

Certain complications can occur due to BMV. If the technique inflates the lungs too much, they can become damaged.

BMV can lead to air entering the stomach if used incorrectly or for long periods. This can cause a person’s stomach to swell or lead to vomiting.

Vomiting while being ventilated can be dangerous. If a person breathes in their vomit, it can lead to infections such as pneumonia or choking.

BMV is a technique used to ventilate a person in an emergency. It involves a healthcare professional manually pumping oxygen into a person’s lungs using a bag valve mask.

Certain factors can cause BMV to become more difficult, such as a person’s age. However, if done correctly, BMV can be a successful ventilation method.

BMV can cause certain complications if performed incorrectly. This includes lung damage and vomit aspiration.