Cyanosis

Abstract

Cyanotic congenital heart disease should not be deemed merely a bluish discoloration of the tissues resulting from arterial oxygen desaturation. Indeed, it is a multisystem involvement affecting most body systems, including hematologic, vascular, renal, respiratory, and central nervous systems, as well as digits, long bones, and bilirubin kinetics. One of the most important manifestations of cyanosis is the hyperviscosity syndrome, which results from secondary erythrocytosis in response to low systemic arterial oxygen saturation <85 %. In this chapter, we will review the cyanosis classification, underlying congenital heart defects, secondary erythrocytosis, hyperviscosity syndrome, adverse effects, multisystem involvement, and therapeutic and prophylactic measures. We will discuss anticoagulation and aspirin therapy in cyanotic patients as well as the indications for therapeutic phlebotomy and concomitant isovolumic fluid replacement.