When using a bag-valve mask device to ventilate a patient, how many rescuers should ideally be present?

Using a bag-valve mask device to ventilate a patient is most effective when two rescuers are present. This allows one rescuer to maintain a proper seal on the mask while the other rescuer squeezes the bag to deliver breaths.

Having two rescuers enhances the ability to ensure adequate ventilation while minimizing the risk of air leakage and maximizing the effectiveness of the breaths being delivered. The rescuer holding the mask can focus on positioning it correctly over the patient's face and maintaining an optimal seal, while the second rescuer can concentrate solely on the timing and volume of the ventilations provided.

In scenarios with only one rescuer, it becomes challenging to maintain a proper mask seal while also delivering effective ventilations. With three or four rescuers, although they could assist in other tasks, it generally becomes unnecessary and could complicate the situation without significantly improving the effectiveness of ventilation when compared to the two-rescuer method.