Etymed
cyanosis
Definition
Abnormal bluish discoloration of the skin and mucous membranes due to insufficient oxygen in the blood
Clinical context
A 65-year-old man presents to the emergency department with shortness of breath and central cyanosis. On examination, he has bilateral crackles in his lungs and a history of chronic obstructive pulmonary disease. His arterial blood gas shows severe hypoxemia with a PaO2 of 45 mmHg. The cyanosis is due to deoxygenated hemoglobin in his systemic circulation.
Mnemonic
Cyanosis = COLD, OXYGEN, BLUE - Remember that cyanosis indicates poor oxygenation, often from cold extremities or severe hypoxemia