What does "bag-mask ventilation" refer to?

Bag-mask ventilation refers to a method of providing positive pressure ventilation to a patient who is unable to breathe adequately on their own. This technique utilizes a self-expanding bag, often known as a bag-valve-mask (BVM), along with a face mask. When performing bag-mask ventilation, the practitioner carefully seals the face mask over the patient's mouth and nose to create a good airtight connection. By squeezing the self-expanding bag, air is forcefully delivered into the patient's lungs, allowing for the exchange of oxygen and carbon dioxide. This method is crucial in emergency situations where a patient experiences respiratory failure or needs assistance with breathing.

The other options mentioned do not accurately describe bag-mask ventilation. Measuring lung function typically involves spirometry or other diagnostic tests, rather than a ventilation technique. Anesthesia administered with a face mask usually pertains to providing sedatives or anesthesia gases for surgical procedures, which is distinctly different from the emergency ventilation context. Lastly, assessing patient oxygen saturation levels involves the use of a pulse oximeter and is not directly related to the mechanical act of providing ventilation. This reinforces the definition that bag-mask ventilation specifically focuses on aiding a patient's breathing during times of respiratory distress.