Which of the following pressures are additive during mechanical ventilation to become the driving pressure for the inspiratory flow?

A. lung elastic recoil pressure and airway pressure
B. ventilator airway pressure and respiratory muscle pressure
C. ventilator airway pressure and lung elastic recoil pressure
D. lung elastic recoil pressure and respiratory muscle pressure

?ANS: B
A. Incorrect response: See explanation B.
B. Correct response: During mechanical ventilation, the pressure provided by the ventilator (AW) is added to the pressure developed by the patient's respiratory muscles to become the driving pressure responsible for causing the inspiratory flow.
C. Incorrect response: See explanation B.
D. Incorrect response: The lung elastic recoil pressure and respiratory muscle pressure are both required to be overcome by the muscles of inspiration during spontaneous breathing.