The Bag Valve Mask, also known as a BVM, Ambu Bag or manual resuscitator, is primarily used by EMTs to ventilate an unresponsive patient in situations in which the patient's tidal volume is inadequate. It is recommended that when using the BVM, an airway adjunct also be used. To ventilate a patient with a BVM:
- Choose the proper mask. The mask should fit over the bridge of the nose with the base of the mask resting between the lower lip and the chin.
- Position Properly. The rescuer should be positioned at/above the patient’s head.
- Open the Airway. Start in the sniffing position, with the ear to sternal notch aligned in the same plane as this often provides for easier ventilation. If this does not work, try tilting the head backward in a “head-tilt chin lift” maneuver or if a spinal injury is suspected, displace the jaw forward with a “jaw-thurst” to open the airway. Use an airway adjunct if available.
- Provide an adequate seal. The mask should create a tight seal. You should not hear air leaking around edge of the mask while you ventilate the patient. The mask should not be pushed down onto the face, but rather, the patients face should be pulled into the mask without closing off the mouth in a "C" or a "CE" grip. An excellent tutorial on sealing can be found here.
- Ventilate smoothly. At a rate of 1 breath every 5 to 6 seconds, squeeze the BVM bag over 1 to 1.5 seconds with a consistent pressure that is just enough to get visible chest rise on the patient. For an adult patient, this is typically 500 to 600 mL. The ventilations should not be forceful, or too high a volume for the size of patient, as this can force air into the stomach (gastric distention), which could cause vomiting an/or aspiration, or reduce the the lungs ability to fully inflate.
When possible, the bag valve mask should be a two person skill with one rescuer maintaining the mask seal, while the other squeezes the bag. This has been shown to be more effective at delivering adequate ventilation to the patient. One must be careful to ensure that the soft tissue of the neck is not compressed by the rescuer's fingers.
Tips and Tricks[edit | edit source]
- Some BVM's come with a PEEP (Positive End Expiratory Pressure) valve either installed or installable. If PEEP is available it can drastically increase the efficacy of ventilations and help prevent atelectasis.
- Most BVM's in the prehospital setting are self-inflating and are attached to a reservoir bag. Occasionally you may find BVM's with open ended tubes in place of the reservoir bag or BVM's without either a tube or reservoir bag. These are used identically to the BVM with reservoir bag.
- Although the most common use for BVM's is when the patient is unconscious with inadequate ventilations, tracking respirations is another potential use of the BVM when the patient is spontaneously breathing and potentially conscious.
Additional Resources[edit | edit source]
- For a more in depth look at different ventilatory techniques, this Life in the Fast Lane page is a FOAM resource that is incredibly helpful.