A bag valve mask (BVM), often called an Ambu bag, is a crucial tool in emergency medical care used to provide positive pressure ventilation to patients who are not breathing adequately.
When properly used, the bag valve mask delivers a specific volume of air with each squeeze. Based on the provided information, when the bag is squeezed, it will deliver roughly 500-600 ml of air per breath.
Factors Influencing Delivered Volume
It's important to understand that the exact amount of air delivered by a bag valve mask isn't always constant. The volume can vary depending on several factors:
- Rescuer Technique: How forcefully and completely the rescuer squeezes the bag significantly impacts the volume delivered. A full, firm squeeze typically delivers the maximum volume.
- Oxygen Flow Rate: If supplemental oxygen is attached to the bag, the flow rate can influence the concentration of oxygen in the delivered breath and, indirectly, the effective volume of oxygenated air.
- Patient's Breathing Pattern: The patient's own respiratory efforts, if any, can interact with the delivered breath, affecting the actual amount of air that enters the lungs.
Understanding this range and the factors that cause variation is key to providing effective manual ventilation. Proper training emphasizes technique to ensure adequate tidal volume is delivered to the patient.
