N2 Washout Lung Volume Measurement

N2 Washout Lung Volume Measurement is a technique for determining the uniformity of gas distribution in the lungs as well as the behavior of the dependent airways. Works based on the technique of washing N2 out of the lungs, during that time the patient breathes 100% O2 using dilution properties of gases.

• The patient breathes 100 percent oxygen, and all the nitrogen in the lungs is washed out.
• The volume of exhaled air and the nitrogen concentration in that volume are measured.
• The difference in nitrogen volume at the initial concentration and at the final exhaled concentration allows a calculation of intrathoracic volume, usually FRC.