In upper airway obstruction all of the following changes are seen except: (A) Decreased maximum breathing capacity, (B) RV decreased, (C) Decreased FEV, (D) Decreased Vital capacity
Answer is B. Ans. (b) RV decreased(Ref: Ganong, 25th ed/p.628)Increase in residual volume denotes "air trapping" which is classically seen in obstructive lung diseases