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

The function of a bag-valve-mask (BVM) is to provide positive pressure ventilation to patients who are not breathing adequately. When a patient is unable to breathe on their own effectively, the BVM can be used to deliver air (or supplemental oxygen) into the lungs. This device consists of a bag that can be squeezed to push air through a one-way valve and into the airway through a mask that seals over the patient's face.

The design of the BVM allows for controlled ventilation, which is critical in emergencies where a patient exhibits signs of respiratory failure or inadequate breathing. This positive pressure ventilation can help to maintain oxygenation and prevent respiratory acidosis, which occurs when there is an accumulation of carbon dioxide in the blood due to inadequate breathing.

Understanding the primary role of the BVM is crucial in emergency medical situations, as it directly impacts the patient's ability to receive adequate ventilation and oxygenation during critical moments.