Performing bag-valve-mask ventilation: the two-person technique

Effective bag-valve-mask ventilation depends on more than squeezing the bag. Oxygen flow, mask seal, jaw thrust, and airway adjuncts each affect how much oxygen actually reaches the patient's lungs, and how much air ends up in the stomach instead.
This lesson breaks the two-person technique into its components: setting the oxygen flow rate so the reservoir stays full, sizing and placing oral and nasal airway adjuncts, and holding a tight mask seal while providing a jaw thrust with proper hand positioning. It also covers tidal volume, ventilation rate, and how to avoid breath stacking and barotrauma in patients with prolonged expiratory times.

In this lesson from our Advanced Airway Management course you'll learn how to:

• Set the oxygen flow rate to flush and keep the reservoir bag full between breaths
• Size and place oral airways and nasal airways (nasal trumpets) to reduce resistance
• Hold a tight mask seal with jaw thrust using proper hand positioning
• Recognize the common mask-seal mistake that blocks an effective jaw thrust
• Deliver an appropriate tidal volume and rate for the clinical scenario
• Avoid breath stacking and barotrauma in patients with prolonged expiratory times 

Understanding the role of bag-valve-mask ventilation

[0:00]
Bag-valve-mask ventilation, or BVM for short, is a fundamental airway skill for a variety of reasons. It's helpful for supporting ventilation in a patient with reduced mental status, and it is often used to improve oxygenation prior to intubation, or in between intubation attempts. If you can maintain oxygenation and ventilation despite failed intubation attempts, you do not have a failed airway. You have time to formulate additional plans and approaches towards securing the tube. So, in a sense, someone who can bag a patient cannot fail at an airway. We will focus on a two-person technique, since this allows the best possible control over jaw position, mask seal, and controlling the bag valve. 

Setting the BVM oxygen flow rate

[0:38]
The oxygen tubing should be connected to oxygen with a flow rate of at least 15 liters per minute. In fact, it is often recommended to turn the oxygen flow up as far as it will go, where the ball in the oxygen flow meter rises all the way to the top. This is referred to as flush rate because the ball is flush with the top of the meter. That flow should fill the oxygen reservoir. 

Patients take breaths with a flow rate much higher than that steady-state rate, but they will be pulling oxygen from the reservoir, so that makes up for the differential flow rate and prevents the need to entrain room air with each breath.

Understanding bag-valve-mask components

[1:23]
The bag is next. We will go into more detail on how to squeeze that in a moment. There are inlet valves and outlet valves to prevent backflow of expired air into the system and to ensure that only oxygen fills the bag and only oxygen is put into the patient. Expired air will flow out of the side port so that the patient won't rebreathe their own air. Past the outlet port, where the face mask attaches, is where a pressure gauge can be placed, or a PEEP valve, or an end-tidal CO2 detector.

Selecting the correct BVM mask size

[1:55]
Finally, the business end of the bag-valve-mask is the mask, which should be sized to fit over the patient's mouth and nose. Using a bag-valve-mask is totally compatible with nasal cannula oxygen, which will usually be applied in advance prior to bagging in preparation for apneic oxygenation during rapid sequence intubation.

Using oral and nasal airways with bag-valve-mask ventilation

[2:14]
There are a few important devices we should nearly always be using with bag-valve-mask ventilation. These include oral airways and nasal trumpets, also known as nasal airways. The purpose of these devices is to open the path of least resistance from the face, past the oropharynx to the lungs. Nasal airways should be sized by measuring from the patient's nose to their earlobe. Oral airways should be sized by measuring from the corner of the patient's mouth to the angle of their jaw.

Positioning oral and nasal airway adjuncts

[2:45]
When the oral airway is placed optimally, it should sit at the level of the teeth, with the flange of the airway curving around behind the tongue. With a nasal airway, the device should sit deep within the nostril, so that the flute of the airway will extend down into the nasopharynx.

Improving BVM ventilation with airway adjuncts

[3:02]
It should feel strange to you to bag a patient without oral or nasal airways in place. It makes the bagging much easier, decreasing the reliance on a perfect mask seal, reducing pressures needed, and it may reduce the amount that you will insufflate the stomach with each suboptimal breath.

Opening the upper airway with a jaw thrust and chin lift

[3:19]
Once the airways are in place, we want to open the airway as much as possible. Using a jaw thrust and chin lift will open the potential space of the upper airway that would otherwise be occupied by the tongue, creating a challenge for bagging. Let's go over two techniques you can use to effectively hold a tight mask seal while simultaneously providing a good jaw thrust.

Performing the CE mask-seal technique

[3:40]
The first is the CE technique. The second is called the VE technique. With the CE technique, the mask seal is controlled by the index finger and the thumb, while the remaining fingers hook beneath the patient's mandible to provide the jaw thrust. With this technique, your thumb and index finger make a C, and the rest of your fingers make an E.

Performing the VE mask-seal technique

[4:05]
With the VE technique, the mask seal is controlled by the thumb, while the first and second digits press beneath the angle of the patient's mandible to provide the jaw thrust from a more posterior angle. Many operators like this because it provides more control over the jaw thrust itself. With this technique, your thumb and index finger make a V, and the rest of your fingers make an E.

Maintaining a jaw thrust and mask seal

[4:30]
Remember the importance of the jaw thrust with either of these hand positions. The point is to create space behind the tongue by pulling the jaw up into the mask. Avoid the temptation of pushing the mask down onto the face, which is the opposite of a jaw thrust.

Delivering the correct tidal volume with a BVM

[4:47]
The operator should squeeze the bag over the course of about one second. A one-liter bag should be squeezed about halfway to provide 500 cc of tidal volume for each breath. When you bag at this rate, apply proper jaw thrust and mask seal, and use nasal and oral airways effectively, you will reduce as much resistance to airflow as possible. When the airflow to the trachea is optimized, you reduce the rate of inflating the stomach with each breath delivered, decreasing the chances of stomach inflation, vomiting, and aspiration. 

Setting the BVM ventilation rate

[5:23]
The rate of delivered breaths should depend on the clinical scenario. According to Advanced Cardiac Life Support, or ACLS, guidelines, generally, no more than 10 to 12 breaths per minute should be delivered. But if you're ventilating a patient who is profoundly acidotic and requires respiratory compensation, higher rates should be used.

Avoiding breath stacking and barotrauma

[5:44]
It's important to allow the previous breath to exhale fully prior to initiating the next breath. This avoids breath stacking, which leads to increased ventilatory pressures and barotrauma. This is especially important when ventilating a patient with asthma or COPD, where airway obstruction leads to prolonged expiratory times.