Table 101-2 General Features of Hemolytic Disorders General examination Jaundice, pallor Other findings physical Spleen may be enlarged; bossing of skull in severe congenital cases Hemoglobin From normal to severely reduced MCV, MCH Usually increased Reticulocytes Increased Bilirubin Increased (mostly unconjugated) LDH Increased (up to 10X normal with intravascular hemolysis) Haptoglobin Reduced to absent Note: MCV, mean corpuscular volume; MCH, mean corpuscular hemoglobin; LDH, lactate dehydrogenase. The laboratory features of HA are related to (1) hemolysis per se and (2) the erythropoietic response of the bone marrow. In the serum, hemolysis regularly produces an increased unconjugated bilirubin, increased lactate dehydrogenase (LDH), increased aspartate transaminase, and reduced haptoglobin. . | Chapter 101. Hemolytic Anemias and Anemia Due to Acute Blood Loss Part 2 Table 101-2 General Features of Hemolytic Disorders General examination Jaundice pallor Other physical Spleen may be enlarged bossing of skull in findings severe congenital cases Hemoglobin From normal to severely reduced MCV MCH Usually increased Reticulocytes Increased Bilirubin Increased mostly unconjugated LDH Increased up to 10X normal with intravascular hemolysis Haptoglobin Reduced to absent Note MCV mean corpuscular volume MCH mean corpuscular hemoglobin LDH lactate dehydrogenase. The laboratory features of HA are related to 1 hemolysis per se and 2 the erythropoietic response of the bone marrow. In the serum hemolysis regularly produces an increased unconjugated bilirubin increased lactate dehydrogenase LDH increased aspartate transaminase and reduced haptoglobin. Urobilinogen will be increased in both urine and stool. If hemolysis is mainly intravascular the telltale sign is hemoglobinuria often associated with hemosiderinuria and an increase in serum hemoglobin in contrast the bilirubin level may be normal or only mildly elevated. The main sign of the erythropoietic response by the bone marrow is an increase in reticulocytes a test all too often neglected in the initial workup of a patient with anemia . Usually the increase will be reflected in both the percentage of reticulocytes the more commonly quoted figure and the absolute reticulocyte count the more definitive parameter . The increased number of reticulocytes is associated with an increased mean corpuscular volume MCV in the blood count. On the blood smear this is reflected in the presence of macrocytes there is also polychromasia and sometimes nucleated red cells. In most cases a bone marrow aspirate is not necessary in the diagnostic workup if it is done it will show erythroid hyperplasia. In practice once an HA is suspected specific tests will usually be required for a definitive diagnosis of the specific type of HA. .
