TY - CHAP M1 - Book, Section TI - Hemolytic Anemia A1 - Yates, Amber M. A2 - Kline, Mark W. Y1 - 2018 N1 - T2 - Rudolph's Pediatrics, 23e AB - Red blood cells (RBCs) have a normal life span of approximately 120 days. An operational definition of hemolysis, therefore, is accelerated RBC destruction with premature removal from the circulation, which usually causes anemia. Hemolytic anemia can occur in a wide range of clinical settings featuring various etiologies; signs and symptoms reflect the location and severity of hemolysis. Intravascular hemolysis occurs when erythrocytes are destroyed in the blood vessel itself, whereas extravascular hemolysis occurs in the hepatic and splenic macrophages within the reticuloendothelial system. Intravascular hemolysis is often dramatic, with free hemoglobin released into the plasma leading to hemoglobinuria. Examples of intravascular hemolysis include enzyme defects such as glucose-6-phosphate dehydrogenase (G6PD) deficiency or certain immune-mediated processes. Extravascular hemolysis usually results from subtler RBC destruction, typically with chronic splenic enlargement and jaundice. Extravascular hemolysis is more common with RBC membrane disorders such as hereditary spherocytosis. Some forms of hemolytic anemia feature both intravascular and extravascular hemolysis. The degree of anemia depends on how rapidly the erythrocytes are being removed from circulation and how well the bone marrow compensates with increased production of new RBCs. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/03/28 UR - accesspediatrics.mhmedical.com/content.aspx?aid=1182909812 ER -