I was a student nurse when I first witnessed the power of a simple device to save a life. I was doing a placement in the recovery unit when I watched an experienced nurse step into action. A patient had stopped breathing, and in the blink of an eye, the nurse produced what looked like a plastic bag attached to a mask. With practiced movements, she placed it over the patient’s face and began squeezing rhythmically. It was mesmerizing and terrifying all at once.
That device, I later learned, was a Bag Valve Mask, or BVM. In the world of resuscitation, it often makes the difference between life and death. I’ve used this device many, many times since that first day.
Join me on a journey through the complexities of advanced resuscitation techniques that I teach in our HLTAID015 Provide Advanced Resuscitation and Oxygen Therapy Course at My First Aid Course Brisbane. This blog will feature a series of articles breaking down the components of this course, written in a user friendly fashion – the same way I deliver training.
In this blog we’ll focus on the unassuming yet powerful instrument, the BVM. Whether you’re a curious bystander, a budding healthcare professional, or simply someone who wants to understand more about life-saving techniques, this exploration of the BVM will open your eyes to the intricacies of keeping someone alive when every second counts.
Table of Contents
What is a Bag Valve Mask?
Imagine holding someone’s life in your hands – quite literally. That’s what it feels like to use a Bag Valve Mask. At its core, a BVM is a hand-held device used to provide positive pressure ventilation (a fancy way of saying using positive pressure – a squeeze of a bag – to deliver air or oxygen – ‘ breath’ to the lungs) to patients who are not breathing or not breathing adequately. But it’s so much more than that.
A typical BVM consists of three main parts: a flexible air chamber (the “bag”), a one-way valve system, and a face mask. The bag is usually made of self-inflating rubber or silicone. When squeezed, it forces air through the valve and into the patient’s lungs. When released, it re-inflates, ready for the next breath. The valve system is crucial – it ensures that exhaled air doesn’t re-enter the bag, preventing the rebreathing of carbon dioxide.
The face mask, which comes in various sizes to fit different patients, creates a seal over the nose and mouth. Some BVMs also have additional features like pressure relief valves, oxygen reservoirs, and PEEP (Positive End-Expiratory Pressure) valves for more advanced care.
BVMs have come a long way since their inception. The concept dates back to the 1950s, evolving from the need for a more effective method of artificial ventilation during the polio epidemic. (Random trivia: the first self-inflating ventilation bag incorporated bicycle spokes to create an internal spring). Today, you’ll find BVMs in every ambulance, emergency room, and many other healthcare settings. They’re even available in some public spaces as part of emergency preparedness kits.
Why is a BVM Used?
The primary purpose of a BVM is to provide ventilation – that is, to breathe for a patient who can’t breathe for themselves. This might be due to cardiac arrest, respiratory failure, or any situation where a person’s breathing is severely compromised.
One of the biggest advantages of a BVM is its versatility and portability. Unlike mouth-to-mouth resuscitation, it provides a barrier between the rescuer and the patient, making it safer and more hygienic. It’s also more effective than mouth-to-mouth, as it can deliver a higher concentration of oxygen when connected to an oxygen source.
Importantly, a BVM can be used without an oxygen source in emergency situations. While supplemental oxygen greatly enhances its effectiveness, room air (which contains about 21% oxygen) can still provide life-saving ventilation. This makes BVMs invaluable in settings where oxygen tanks aren’t immediately available, such as in remote locations or during transport.
Moreover, a BVM gives healthcare providers greater control over the volume and pressure of air delivered to the patient. This is crucial in situations where too much or too little air could be harmful. For instance, in cases of head injury, precise control of ventilation is essential to manage intracranial pressure.
The scenarios where a BVM becomes a lifesaver are numerous. Consider a drowning victim pulled from a pool, a person suffering from a severe asthma attack, or someone who’s had a drug overdose. In all these cases, a BVM could be the bridge that keeps them alive until more advanced medical care is available.
How is a BVM Used?
Using a BVM effectively is both an art and a science. It requires practice, skill, and a good understanding of human anatomy. Let’s break down the process step by step:
1. Positioning: Place the patient on their back on a flat surface. Tilt their head back slightly to open the airway. If available and appropriate, insert an oropharyngeal airway (more on these in Airway Adjuncts blog) to help maintain an open airway. This can be particularly useful in unconscious patients where the tongue might obstruct the airway.
2. Choose the right size mask: It should cover the mouth and nose without extending past the chin or eyes.
3. Create a seal: Place the mask on the patient’s face, using the traditional C-E grip.
This involves forming a ‘C’ shape with your thumb and index finger on top of the mask, while your other fingers create an ‘E’ shape to lift the jaw. This grip can be modified as needed based on hand size and patient facial structure.
The goal is to create an effective seal while simultaneously lifting the jaw to open the airway. An effective seal is essential to ensure the ‘breath’ is delivered to the lungs, not lost to the air due to a leak.
4. Squeeze the bag: Use your other hand to squeeze the bag firmly but not forcefully. Each squeeze should last about 1 second and should be enough to make the patient’s chest rise.
5. Release and allow the chest to fall: This lets the patient exhale.
6. Repeat: Aim for about 10-12 breaths per minute. In a first aid CPR situation, two breaths are delivered in the pause after each 30 chest compression. The usual 30:2 compressions to breaths is maintained throughout the resuscitation event.
While it might sound straightforward, there are many nuances to using a BVM effectively. One common mistake is squeezing the bag too hard or too fast. This can force air into the stomach instead of the lungs, leading to complications. Another is not maintaining a proper seal, which reduces the effectiveness of each breath.
Human anatomy and facial structure can significantly influence BVM usage. Patients with beards, for instance, can make it challenging to create an effective seal with the mask. In such cases, additional techniques like using two hands to hold the mask can help. Similarly, patients with facial trauma, unusual facial structures, or those who are edentulous (without teeth) may require special techniques to ensure proper ventilation.
Here’s a pro tip: If you’re having trouble getting a good seal or if the patient’s chest isn’t rising, try repositioning their head slightly or adjusting your grip on the mask. Sometimes, a small change can make a big difference. Take care not to apply any pressure on the patient’s eyes either with the mask or your own hands.
For optimal effectiveness, BVM ventilation can be performed as a two-person operation. One person uses both hands to maintain a tight mask seal and proper head positioning, while the other focuses solely on squeezing the bag. This technique often results in more effective ventilation, especially in challenging situations. (This is a particularly handy tip for responders who have beginner skills. There’s no shame in asking for assistance.)
This technique is easily undertaken in a CPR event, as the responder providing chest compressions can squeeze the bag after 30 compressions, while the other responder maintains a good seal on the mask. It takes practice – something you will do in the practical part of your My First Aid Course.
Advanced Considerations
As with any medical technique, using a BVM isn’t one-size-fits-all. The approach needs to be tailored based on the patient’s age and condition. For instance, infants and small children require much smaller tidal volumes (the amount of air moved in and out of the lungs with each breath) compared to adults. The technique for sealing the mask is also different – for babies, you create a seal using the thumb and index finger, while the other fingers lift the jaw.
Recent developments in BVM technology are making these devices even more effective. Some modern BVMs come with built-in pressure manometers, allowing rescuers to monitor the pressure of each delivered breath. Others incorporate filters to protect against airborne pathogens – a feature that became particularly valuable during the COVID-19 pandemic.
Researchers are also exploring ways to improve BVM design for easier use by less experienced rescuers. One promising direction is the development of ‘smart’ BVMs that provide real-time feedback on ventilation quality, potentially improving outcomes in emergency situations.
Grow Your Life Saving Knowledge
From its humble beginnings to its current status as a cornerstone of resuscitation, the Bag Valve Mask has proven itself time and again as a life-saving device. Its simplicity belies its importance – in the right hands, it’s quite literally a breath of life for those in dire need.
Understanding the what, why, and how of BVM use gives us a deeper appreciation for the complexities involved in emergency medical care. It’s a reminder of the delicate balance between human skill and technological innovation that characterizes modern medicine.
Whether you’re a healthcare professional, a first responder, or simply someone interested in the mechanics of life-saving, I hope this exploration of the BVM has been enlightening. Remember, while knowledge is power, practical skills save lives. If you’re inspired to learn more, consider undertaking HLTAID015 Provide Advanced Resuscitation and Oxygen Therapy Course at My First Aid Course Brisbane. It’d be great to meet you! You never know when you might be called upon to be someone’s lifeline.
