Cyanosis NOT improving with 100% oxygen in case of: (A) Cardiac asthma, (B) Interstitial lung disease, (C) Bronchial asthma, (D) Tetrology of hea
Answer is D. Presence of cyanosis that does not improve with supplemental oxygen suggest true pathological cardiac or pulmonary shunting of blood . Ref Harrison 19th edition pg 1248-49