Prehospital Ventilation is in the Bag with Proper Technique and Appreciation

EMS ventilation using bag valve mask
A 1970s-era Puritan Manual Resuscitator (PMR) bag-valve mask, affectionately referred to as "the football." Photos A.J. Heightman

As a 16-year-old observer on the ambulance with my father, I wasn't allowed to ventilate unconscious patients, but I watched and learned a great deal by just observing how they used their "football," an early Puritan Manual Resuscitator (PMR) bag-valve mask (BVM). They nicknamed it the "football" not just because it was brown and resembled a football, but because it was easier to tell the firefighters or police officers assisting them to "go get the football" than "go get the BVM."

I was curious why my dad placed rolled towels or a blanket under the patient's shoulder blades and neck, and then placed his knee against the top of the patient's head that was extended back toward him.

He explained that the padding raised the patient's upper torso and placed the patient into a head-back position that opened their airway like a "wide-open rain gutter." He added that the knee he placed against the patient's head helped keep their head from moving forward. Both actions optimized ventilation by keeping the airway of a non-traumatized patient open to its most effective position. It was an impressionable lesson I never forgot.

After college I became an EMT but never really appreciated the importance of proper BVM ventilation until I entered paramedic training in Allentown, Pa., in 1977. Through no fault of their own, my EMT instructors, using an 81-hour curriculum, only had so much time to teach ventilation support with a BVM. Emphasis was on inserting an oropharyngeal airway into unconscious patients, getting a face seal with the mask to interpose breaths on cardiac arrest patients once every fifth compression, or ventilating those in respiratory arrest once every 3–5 seconds to achieve a 12–20 ventilation rate. Other than that., there wasn't a lot of emphasis on technique or mask sizing in EMT training back then.

In training, we all used the same style Laerdal BVM and became spoiled because the mask on this early BVM had the most comfortable and easy-to-seal mask assembly I ever used. Its dome shape allowed even the smallest hand to get a perfect seal because pressure could be evenly distributed down and across the facial region.

I learned that all masks weren't as easy to seal when I took my practical exam and the testing team gave me a Hope Resuscitator BVM with a different style mask that had a wide ventilation port on the top.

And, because we were taught in a staged classroom, we really weren't prepared for real-world cases and complications such as ventilating patients trapped upside down in a car, patients with facial trauma, small children and infants, or the frail, elderly patient found unresponsive without her dentures in place.

Sure we ventilated the pristine, intact Resusci Anne on the floor of our classroom, but there's so much more needed to make an EMS provider comfortable and competent in BVM resuscitation.

EMS ventilation using bag valve mask
The dome-shaped mask on this early Laerdal BVM allowed crews to get a
perfect seal because pressure could be evenly distribution across
the face by even the smallest hand.

Enter Dr. Blaisedell

During my paramedic training, where a significant amount of time was placed on ventilating patients, Anesthesiology Chief Willaim Blaisdell, MD, took me and 20 other raw paramedic recruits under his wing and guided us through a ventilator stewardship in the operating room (OR) of Allentown's (Pa.) Sacred Heart Hospital at a time when paramedics were being refused entry into ORs in many hospitals.

We were an unknown and unproven commodity in the field of medicine and many anesthesiologists said, "They're not going to take over ventilatory support or intubate my patients!"

However, our paramedic medical director, George Moerkirk, MD, an inspired surgeon turned EMS zealot, convinced Dr. Blaisdell of the importance of not just paramedics, but the work we would be doing as physician extenders in the field.

In a brilliant move, Dr. Moerkirk persuaded Dr. Blaisdell to attend not only the respiratory module of our program, but also the first few lectures where we were taught what the scope and impact of our work would be. That solidified his interest. He adopted us and convinced the other anesthesiologist to welcome us into their OR.

Early in our training, Dr, Blasedell had us take deep breaths in a standing position. He then had us place our chins down as far as we could on our chest, pressing down against our sternums, and take a few deep breaths. It was difficult.

He then told us to bring our heads back toward the center of our shoulder blades, open our mouths and take a few breaths. The difference, and volume of air we could exchange, was dramatically different.

Dr. Blasedell then had us line up against the classroom walls and pointed out that, while our ankles, butts, backs and shoulders were flush against the wall, our heads and necks were still 2–4 inches away from the wall. He noted that, consequently, when a patient is supine on the floor, a street or an OR table, elevation of their shoulders assisted in aligning their trachea and oropharynx for effective "bagging" and direct vocal cord visualization. It was an important teaching moment I never forgot and have passed on to students for 40 years.

These classroom lessons came to life in the OR, where we were invited to watch an operation, and where they also put towels under the patient's head like my dad taught me to do 10 years earlier.

It was an intimidating experience for a 23-year-old rookie to report to an OR early in the morning and have an anesthesiologist go over the day's cases on a whiteboard as we scrubbed up with the rest of the staff.

Although honored to be allowed to be a part of the OR team, I was in awe of the staff and felt like a medical neophyte entering into their sterile and demanding world. More daunting was the fact that I and my fellow students were being placed on center stage and required to work on live patients who were intentionally sent into respiratory arrest, often needing ventilation by the staff for over an hour.

The anesthesiologists told us the complications we might encounter in ventilating each patient. Some had no dentures in place, others had abnormal facial features or beards that affected our ability to get a proper seal, and some had the famous jutting jaw that we soon learned made intubations difficult.

To add more stress, we were expected to identify the patient's best veins and cannulate them after first injecting 2% lidocaine under their shin to temporarily numb the site. That was great for the patient because it diminished the pain and pressure of the IV stick, but the injected lidocaine fluid hid the vein and necessitated a lot of palpation on our part to be successful.

We were also required to calculate the medication being used to put the patient in "la-la-land" for their operation. I can joke about it now, but, at the time, it was so very frightening to be required to calculate the appropriate dose and then inject it slowly into the IV I had just started, until they were unconscious and wouldn't feel any of pain during the operation.

As the anesthesiologist started to bag the patient as they dozed off, we had to move to the head of the operating table and take control of the patient's airway. We had to evaluate and articulate what we observed about each patient's airway and respiratory rate, select the appropriate size mask for the patient, apply it properly to their face, position their head properly and take over ventilations for them—with six sets of eyes watching our every move! This is where I truly learned how to master BVM use and patient ventilation.

It was here where Dr. Blasedell told us that the BVM was one of the most important tools of our new profession, and that we had to master its use because it was truly a bridge between life and death for our patients. He added that we should always have a BVM with us in the field to start ventilations immediately and not delay proper care until someone ran to the ambulance to retrieve one.

Once we bagged each patient at the right rate and depth, and evaluated pulse oximetry and capnography—which wasn't being done in the field at the time—we were directed to reposition the patient's head for intubation. Dr. Blasedell and his staff required us to visualize the cords and deliver a mist of lidocaine between them via a syringe with a long extension tube. This numbed the area prior to tube introduction.

The first time I was asked to do this I realized that not only was I being asked to perform an extra step I wouldn't be doing in the field, but that, technically, I was being required to visualize and introduce an object through the cords twice!

It was a double experience that also doubled our skill enforcement—again, another important lesson other paramedic programs weren't able to offer their students at the time.

EMS ventilation using bag valve mask
The inexpensive and fun "Watermelon Man" teaches crews respect for suctioning and BVM skills.

Lessons Learned

There are several key messages here that I want to emphasize:

1. We must teach crews to master use of their BVMs. It helps to make early EMS education fun, highly visual and informative by use of training aids like my homemade "Watermelon Man" that teaches crews respect for suctioning and BVM skills. For a step-by-step construction of this inexpensive training aid, visit the JEMS Editor Blog.

2. Have a BVM with you at all times because you never know when it will be needed. In today's world of increasing overdoses, compact BVMs like the 3" x 5" Cyclone BVM by North American Rescue can be carried in each kit or airway bag for ready access and use.

EMS ventilation using bag valve mask
The 3" x 5" Cyclone BVM can be carried in any kit for ready deployment whenever necessary.

3. Master the use of your BVM because it's truly one of the most important pieces of equipment you'll ever use;

4. Use an oropharyngeal or nasopharyngeal airway to maintain an open airway and augment ventilation;

5. Use padding under the patient and align the patient's external auditory meatus
with the sternal notch (ear-to-sternal notch position);

6. Have a suction unit with you whenever you bag a patient;

7. Depress the bag for a full 1–2 seconds and then release it. You should be able to visualize chest rise with adequate tidal volumes (i.e., approximately 6–7 cc/kg or
400-600 mL);1,2

8. Always monitor oxygenation and ventilation via pulse oximetry readings.

9. Don't hyperventilate patients because it's been demonstrated that hyperventilation can be harmful by increasing intrathoracic pressure, which decreases venous blood to the heart and subsequently decreases cerebral and coronary perfusion pressures.3,4

The old saying, "It's in the bag," is truly applicable to prehospital ventilation. You must master BVM use because your patient's life depends on it.

References

  1. Hirshon JM: Basic cardiopulmonary resuscitation in adults. In Tintinalli JE, Kelen GD, Stapczynski JS (Eds.): Emergency medicine: A comprehensive study guide. 6th Edition. McGraw-Hill Publishing: New York City, 2004.
  2. Levitan RM: The airway-cam guide to intubation and practical emergency airway management. Airway Cam Technologies: Wayne, Pa., 2004, 49–71.
  3. O'Neill JF, Deakin CD. Do we hyperventilate cardiac arrest patients? Resuscitation. 2007;73(1):82–85.
  4. Aufderheide TP, Sigurdsson G, Pirrallo RG, et al. Hyperventilation-induced hypotension during cardiopulmonary resuscitation. Circulation. 2004;109(16):1960–1965.

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