According to various embodiments, methods and systems for determining pressure in the lungs may employ tracheal pressure measurements. The tracheal pressure measurements may be obtained through a pressure monitoring lumen associated with a tracheal tube. Such systems may include a purging or flushing mechanism to keep the pressure monitoring lumen free of any obstructions. The flushing mechanism may utilize fluids delivered through the pressure monitoring lumen at a predetermined point in the breathing cycle and/or at a predetermined pressure relative to the respiratory gases. The resulting pressure measurements may be used to determine a more accurate estimate of lung pressure, which in turn may be used to control a ventilator and provide breathing assistance to a patient.
