What evidence suggests improper BVM positioning?

Inadequate chest rise and insufficient ventilation are strong indicators of improper positioning of the Bag-Valve-Mask (BVM). When the BVM is not positioned correctly, it may not create a proper seal around the patient's mouth and nose, leading to ineffective delivery of air. This can result in little to no movement of the chest, signifying that air is not reaching the lungs adequately, and hence the gas exchange is compromised.

Proper BVM technique requires ensuring that the mask is sealed effectively on the face, ensuring not only adequate chest rise but also confirming that ventilation is efficient. Observing that there is inadequate chest rise is a key clinical sign that something is amiss with the BVM positioning or technique, prompting reassessment and repositioning as necessary to ensure that the patient receives proper ventilation. This is particularly critical in emergency situations where effective airway management can be lifesaving.