What is the function of a bag-valve-mask (BVM)?

The function of a bag-valve-mask (BVM) is specifically to provide breaths to a person who is not breathing adequately or at all. This device allows a rescuer to deliver positive pressure ventilation to the patient’s lungs. It consists of a self-expanding bag, a unidirectional valve, and a facial mask. When the bag is squeezed, air is forced through the valve and into the patient’s lungs when the mask is properly sealed against the face.

While other choices focus on aspects of emergency response, they do not capture the primary use of the BVM. For instance, checking responsiveness and securing the airway are essential steps in the assessment and treatment of a patient, but they do not involve providing the act of ventilation. Similarly, while CPR is a crucial life-saving technique involving chest compressions and rescue breaths, the BVM specifically enhances the ability to provide those rescue breaths effectively, particularly in cases where the airway is at risk or requires support due to insufficient natural breathing. Therefore, providing breaths is the key function that defines the use of a BVM.