When using a bag-valve-mask to ventilate, what is crucial to ensure adequate ventilation?

Ensuring a proper mask fit is crucial for adequate ventilation when using a bag-valve-mask (BVM) because a well-fitted mask creates a tight seal against the patient's face. This seal is essential to prevent air leakages during positive pressure ventilation, which would otherwise compromise the effectiveness of the ventilation. An improper fit can lead to inadequate delivery of oxygen to the lungs and can cause the rescuer to have to exert more effort, leading to fatigue and potential failure to provide effective ventilation.

In addition to the fit of the mask, factors such as the size of the mask, speed of squeezing the bag, and the use of airway adjuncts may contribute to the overall success of BVM ventilation, but none are as fundamentally critical as achieving a proper seal with the mask. If the mask does not fit well, other efforts to ventilate effectively may be rendered moot, leading to inadequate oxygenation and ventilation of the patient.