Systems and methods for flushing an assessment catheter

A pulmonary diagnostic system, comprising:

• a pulmonary catheter configured to be introduced transtracheally into an air passage of a lung segment, wherein the pulmonary catheter comprises a distal portion, a proximal portion, and a lumen disposed therein between the distal and proximal portions;
• an external console coupled to the proximal portion of the pulmonary catheter and configured to monitor exhaled air flow;
• and
• a flushing element coupled to a pressurized gas chamber and the proximal portion of the pulmonary catheter, wherein the flushing element comprises a release valve that is configured to deliver clearing gas to the lumen of the pulmonary catheter from the proximal portion to the distal portion with sufficient force to dry or push mucus from the lumen and into the air passage of the lung segment and away from the external console to prevent impeding of air flow and interfering with the monitoring function of the external console.