Final answer:
An adult apneic patient requires about 500 to 600 milliliters of air during each ventilation, equal to the normal tidal volume of quiet breathing.
Step-by-step explanation:
When ventilating an adult apneic patient, the volume of air required during each ventilation is typically about 500 to 600 milliliters, which is similar to the normal tidal volume (TV) during quiet breathing. It is crucial to avoid over-ventilation, which could lead to complications such as gastric inflation and increased intrathoracic pressure potentially reducing cardiac output. In the context of health and emergency care, it is important to ensure that the air delivered matches the patient's physiological needs, adhering to current resuscitation guidelines.