Question

Cyanosis 

A. May be caused by high levels of carboxy hemoglobin in the blood. 

B. May be caused by high levels of met hemoglobin in the blood. 

C. Is seen in fingers of hands immersed in iced water. 

D. Occurs more easily in anaemic than in polycythaemic patients. 

E. Is severe in cyanide poisoning.

Answer 1

A. False Carboxy hemoglobin is pink and gives the skin a pinkish colour. 

B. True This blue pigment is a rare cause of central cyanosis. 

C. False The fingers are red; cold inhibits oxygen dissociation and reduces metabolism. 

D. False Cyanosis occurs when arterial blood contains more than 5 g/dl reduced hemoglobin; low hemoglobin values in anaemia make it difficult to reach this level. 

E. False Cyanide poisons the enzymes involved in O₂ uptake by the tissues; in cyanide poisoning the blood remains fully oxygenated and the skin is pink.