What is the purpose of a Bag-Valve-Mask?

The Bag-Valve-Mask (BVM) is primarily used to assist in manual ventilation of patients who are unable to breathe adequately on their own. This device comprises a self-expanding bag connected to a unidirectional valve and a facial mask. When the bag is squeezed, air is pushed into the patient's lungs through the mask, effectively providing the necessary ventilation. The design helps ensure that the ambient air does not enter the patient's lungs, delivering a controlled volume of air or oxygen directly to the airway, vital for patients experiencing respiratory distress, unconsciousness, or respiratory failure.

While delivering high-flow oxygen and providing non-invasive ventilation support are important in emergency settings, they are not the main goal of the BVM. The device's primary function is to enable a healthcare provider to manually ventilate a patient, especially when the patient is unable to breathe on their own or when there is a need to support respiration temporarily. Furthermore, measuring blood oxygen saturation is typically conducted using a pulse oximeter, not through the use of a BVM, thus highlighting the specific role of the BVM in facilitating manual ventilation.