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Patient Care

Getting a Better Seal

In EMT class we learn that patients with inadequate respirations need to be ventilated to receive positive-pressure ventilation. Inadequate respirations can be caused by inadequate tidal volume, inadequate rate, or a combination of both. The most common tool used by EMTs to provide this positive pressure is the bag-valve mask (BVM).

The optimum way to provide ventilations with the BVM is a two-person operation where one provider opens the airway using the head tilt-chin lift or modified jaw thrust maneuver while using two hands to seal the mask securely to the patient’s face. The other provider squeezes the bag connected to supplemental oxygen to ventilate the patient (Photo 1).

One common EMT skill that should be avoided is the one-person BVM operation. When a single rescuer holds open an airway, one hand squeezes the bag, and the other makes the “OK” symbol and places fingers under the patient’s chin to lift. This by itself could be a possible airway obstruction.

While a two-person BVM operation is optimal, with a two-person EMS crew it isn’t always possible. In the operating room anesthesiologists often use a special mask and latex head strap to help secure it. An alternative for EMS could be using an anesthesia mask and strap as a BVM aid in the field (Photo 2).

Providers know CPAP needs a good seal to be effective. A combination of latex or elastic straps is used to secure the CPAP mask around the head to the patient’s face. If the seal isn’t good, the obvious sign is leaking air and continued ineffective breathing. With the BVM crews often think they have a good seal when they really don’t. An anesthesia mask and strap hold the seal so the rescuer can focus on the open airway and effective ventilation support. Additionally, all BVMs should be equipped with a PEEP valve.

If you have a patient with facial hair that gets in the way of a mask seal, either a quick shave with the razor from your AED or a well-placed Tegaderm sticker can help create a better seal.

While ventilating patients, especially large or obese patients, placing them in a ramped position (stacking blankets behind the patient’s upper body and head until the tragus aligns with the sternal notch) can help reduce the pressure on the diaphragm and makes it easier to ventilate. Large patients are associated with difficult BVM ventilations.1 Providers can improve their ventilation techniques for obese patients by utilizing multiple airway adjuncts (NPA and OPA at the same time), utilizing two providers to control an airway, and adjusting the patient’s position. Another option is to sit the patient up in a high Fowler’s position if that helps control the airway better.

For only slightly more than a traditional disposable BVM and mask, buying an anesthesiology mask and head strap can allow your smaller crews to work more effectively and efficiently while providing ventilatory support.


1. Yildiz TS, Solak M, Toker K. The incidence and risk factors of difficult mask ventilation. J Anesth, 2005; 19(1): 7–11.

Barry A. Bachenheimer, EdD, FF/EMT, is a frequent contributor to EMS World. He is a career educator and university professor. Active in EMS since 1986, he is currently a firefighter with the Roseland (N.J.) Fire Department and an EMT with the South Orange (N.J.) Rescue Squad. He is also an instructor at the National Center for Homeland Security and Preparedness in New York. Reach him at

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