In a data collected from nitrogen wash-out method in a patient, volume of nitrogen was found to be 800 mL in his residual volume (RV). How much is the RV in this patient?
400 mL
800 mL
1000 mL
1600 mL
In all the respiratory volumes, 80% fraction is of nitrogen. Thus, if total nitrogen volume in the RV is 800 mL, then RV is 1000 mL. (80% of 1000 mL is 800 mL.)
Respiratory System Pa 1