Bag-Mask Ventilation

Bag-Mask Ventilation in BLS: Technique and Common Mistakes

Effective breaths are a core skill on every BLS course, and the bag-mask is the device most healthcare providers will use. It looks simple and is surprisingly easy to do badly.

The essentials

Open the airway, seal the mask with the E-C clamp, give each breath over about 1 second, just enough to make the chest rise, and never over-ventilate. With two rescuers, one holds the mask with both hands while the other squeezes the bag.

Pocket mask first

The pocket mask is the simplest barrier device and is taught first. Seal it with both hands, open the airway with a head tilt–chin lift, and breathe in until the chest rises.

The E-C clamp

Thumb and index finger form a “C” pressing the mask onto the face; the other three fingers form an “E” lifting the jaw into the mask. Lift the jaw to the mask rather than pushing the mask onto the face.

Two-person bag-mask

A single rescuer often cannot keep a good seal while squeezing the bag. With two rescuers, one holds the mask with both hands and the other squeezes. This is why two-rescuer BLS is the clinical standard.

How much and how fast

  • Each breath over about 1 second, just enough for visible chest rise.
  • During CPR: 2 breaths after every 30 compressions (15 for two-rescuer child and infant CPR).
  • With a pulse but inadequate breathing: about one breath every 6 seconds for adults, every 2 to 3 seconds for children and infants — see the pulse check.

Common mistakes

  • Squeezing too hard or too often — over-ventilation reduces blood returning to the heart.
  • A poor seal, with air leaking around the mask.
  • Wrong mask size, especially for infants and children.
  • Long pauses in compressions to ventilate.

This guide summarises what is taught on the course. The American Heart Association CPR and ECC Guidelines, linked below, are the authoritative source.

Other life support and first aid courses: ACLS Course · PALS Course · First Aid Course · Training calendar

Frequently asked questions

What is the E-C clamp technique?

Thumb and index finger seal the mask in a C shape while the other fingers lift the jaw in an E shape.

How long should each breath take?

About 1 second, just enough to make the chest rise.

Why is over-ventilation harmful?

It raises pressure in the chest and reduces blood returning to the heart.

Is bag-mask ventilation part of BLS?

Yes, for healthcare providers, alongside pocket mask ventilation.

Is two-person bag-mask better?

Yes, it usually gives a much better seal.

Practise these skills on an AHA BLS course

Reading is not the same as doing. Safety First Medical Services is an American Heart Association training centre on Al Reem Island, Abu Dhabi, with classroom, HeartCode and on-site BLS training and a two-year AHA BLS Provider eCard.

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Sources and further reading

What we teach follows the awarding body and the UAE health authorities. For the definitive position on a course or licensing question, these are the places to check.

Last reviewed by the training team at Safety First Medical Services, an American Heart Association training centre at Addax Office Tower, Al Reem Island, Abu Dhabi. Call +971 55 761 9841 or email training@safetyfirstmed.ae.