One of my readers recently asked a very important question about ventilating a patient with a bag-valve-mask device: “Is there an outlet for the expired air of the patient?” The answer is yes. When ventilating a patient we are concentrating, and rightfully so, on watching the lungs expand and verifying that we hear breath sounds. It is just as important to verify that your patient can exhale. All ventilation devices have a built in pressure relief valve, also called a pop-off valve, which allows you to balance the force needed to expand the lungs with the ability to the patient to passively exhale. Failure to allow exhalation can lead to patient injury from barotrauma.
Common parts for bag-valve-mask devices, In this case a self-inflating style bag. Note the pressure relief valve near the mask elbow. This valve regulates inspiratory pressure as well as effects ease of exhalation.
We have just finished another round of Critical Event Training for my hospital’s Anesthesia and OR staff. One of the scenarios we ran was how to manage a failed airway: the dreaded “can’t intubate-can’t ventilate” scenario.
As an instructor, it’s important for me to set the stage realistically. The more real the scenario, the more the providers will learn and be able to apply the information should they ever find themselves in a comparable situation. I must observe as the trainees respond to the emergency, and then help the trainees self-analyze what went well — or not so well — during the scenario. Of course, discussion of how things went during a training scenario always leads to sharing of examples from past real life scenarios. And after 37 years of practice I’ve had a lot of sharable experiences.
One past case we discussed is particularly appropriate for those students around the country who are just beginning to learn airway management because the solution rested in basic airway management techniques. This case, involving an intubation in an ICU patient that turned into a “can’t intubate/can’t ventilate” emergency demonstrates how returning to the basics of airway management can sometimes be the way to save your patient from harm. All illustrations from Anyone Can Intubate 5th Edition. Continue reading →
Ventilating with a bag-valve-mask device requires a good mask seal against the face in order to generate the pressure to inflate the lungs. But it also requires knowledge of how to effectively use the ventilation device to deliver a breath. This article will discuss the differences in ventilation technique for self-inflating vs free-flow ventilation bags. Understanding those differences is important for you to successfully ventilate your patient. Continue reading →
Since its invention, the Laryngeal Mask Airway, or LMA, has become quite valuable as a surgical airway alternative to intubation. When I first started in anesthesia, the only way to avoid intubation during surgery was to manually assist ventilation with a bag-valve-mask attachment. Cases that went on for hours often resulted in cramped fingers, and sometimes progressively poorer ventilation over time as the hand holding the mask became overly tired. A poor mask seal could potentially cause the stomach to distend with air, pushing up the diaphragms, limiting tidal volume, and increasing the risk of aspiration. The LMA has changed anesthesia so much that residents now find it challenging to find cases to practice their masking skills.
However, the LMA is so commonly used, and so apparently safe, that it’s easy to become complacent. Research is showing that it’s apparently very common for us to over-inflate our LMA cuffs — to the potential harm of our patients. Continue reading →
Those of us who ventilate patients have all been there. We’ve been ventilating a patient with a bag-valve-mask device during a prolonged and difficult intubation process and our hand holding the mask starts to cramp.
As an anesthesia provider I often ventilate patients with bag-valve-mask devices. Of course we need to know how to manage the airway during emergency situations in the ICU or emergency room. When we administer general anesthesia, we mask ventilate both at the beginning and at the end of a case.
For some surgical procedures we may even allow the patient to breathe anesthetic gas spontaneously through a mask during the entire surgical procedure, requiring us to hold the airway open, assist ventilation as needed, and stay out of the surgeon’s way. Laryngeal mask airways are often used these days for such cases, but in the old days the choice was either mask ventilation or intubation.
When ventilating a patient with a mask, it’s important to know how to open and airway and provide positive pressure breaths. However, it’s also important to know how to do so in a way that conserves your grip strength. Ventilating with a mask can be very tiring to your hand. Prolonged “masking” can tire your hand to the extent that you lose grip strength and coordination — making maintenance of an open airway harder to sustain over time. When I’m working with a new student, and when appropriate to the case, I often have them hold the mask during the entire anesthesia because it helps them improve their skills. So how do you effectively and efficiently ventilate while minimizing hand fatigue? Let’s look at the steps to follow. Continue reading →
When we place anything in the mouth, be it an endotracheal tube, oral airway or LMA, we are typically extremely careful to protect the teeth. We take care to avoid cutting the lips with the teeth. But we often take the safety of the tongue for granted. I recently recognized a potential problem while using an LMA supreme that could have caused tongue ischemia if not corrected. Let we show you what happened so you can be on guard with your own patients. Continue reading →
As an anesthesiologist, I often run to emergencies where the patient is not breathing adequately and requires intubation. However, before any intubation, a patient in respiratory distress/failure needs ventilation. Providers who have passed ACLS are often able to ventilate an apneic patient well because they have practiced on the manikin.
However, I often see that providers have more difficulty assisting the ventilation of a patient who is still breathing spontaneously. The typical inexperienced provider will try to provide large, slow breaths just as they were taught in ACLS. Unfortunately these breaths are often out of synch with the patient’s own breathing. Squeezing the bag while the patient is exhaling means that your inflation pressure must not only overcome the diaphragm, but also reverse the passive outflow of air, the elastic recoil of the lungs, and the rebound of the chest wall combined. The vocal cords may be closed. Ventilating out of synch with the patient won’t be as effective. The breath you deliver will take the path of least resistance to enter the stomach or escape from the mask. It often makes the patient cough.
Even worse, providers will occasionally hesitate to try to assist a patient’s breathing while waiting for the intubation team because they feel they don’t know how. Delay in improving ventilation can place your patient at higher risk of complication. This is unfortunate because in many ways assisting ventilation is even easier than manually ventilating an apneic patient. Let’s see why. Continue reading →