Which device is used to deliver ambient air to a patient effectively?

The bag-valve-mask (BVM) resuscitator is specifically designed to deliver ambient air, or supplemental oxygen, to a patient in a controlled manner. This device consists of a bag that can be squeezed to force air or oxygen into the lungs, a unidirectional valve to prevent exhaled air from returning to the bag, and a mask that fits over the patient's nose and mouth to create a seal.

The BVM is particularly useful in emergency situations where a patient is unable to breathe adequately on their own. By providing positive pressure ventilation, the BVM ensures that the patient receives sufficient air supply, especially when their natural respiratory efforts are compromised. The design allows for quick, efficient delivery of air directly to the respiratory system, making it a critical tool in pre-hospital and emergency care settings.

Other devices listed, such as an automated external defibrillator (AED), oxygen cylinder, and ventilatory mask, serve different purposes. The AED is primarily for analyzing heart rhythms and delivering shocks to correct life-threatening arrhythmias. An oxygen cylinder is used to store and provide concentrated oxygen but does not assist in the manual delivery of air or require a caregiver to provide ventilations. The ventilatory mask may refer to a simple