Anesthesia provider asks the patient to take 4 deep breaths by intermittently stating "take as deep a breath as you can". This is the standard of care technique for preoxygenation before induction of general anesthesia with the end point being 80% expired oxygen. The breath volumes in milliliters are recorded but not stated to the patient.

Anesthesia provider asks the patient to take 4 deep breaths but provides coaching by informing the patient of the numeric volume (milliliters) to reach for every breath. Each tidal volume breath is measured using the anesthesia ventilator and the provider encourages the patient to achieve a higher tidal volume than previously achieved. For example, if the initial tidal volume achieved by the patient is 500 milliliter, the provider states, "that was a 500 milliliter breath, now try to achieve a 1000mL breath". The numeric goal should continue to increase above the patient's actual tidal volume. The breath volumes are recorded.

Tidal volume breath measured in milliliters

Measured vital capacity breaths volume in milliliters