0071643192.pdf

HEMATOLOGY, ONCOLOGY, ALLERGY,

AND IMMUNOLOGY

TABLE 9.1. Classification of Anemia

TYPE PATHOPHYSIOLOGY CAUSES

Microcytic anemia Decreased production Iron deficiency

(MCV<80 fL) of hemoglobin Thalassemia

Anemia of chronic disease

Lead poisoning

Sideroblastic anemia

Macrocytic anemia Decreased DNA Vitamin B 12 deficiency

(MCV>100 fL) synthesis Folate deficiency

Sulfa drugs

Alcohol abuse

Normocytic Decreased marrow Hemorrhage

anemia production of RBCs or Hemolysis (G6PD deficiency, hereditary

increased loss or spherocytosis, microangiopathic hemolytic

destruction of RBCs anemias)

Aplastic anemia

Sickle cell disease

Anemia of chronic disease

Anemia of renal disease

An HIV-positive African American male recently began trimethoprim-

sulfamethoxazole for PCP prophylaxis. The patient presents to the ED with

shortness of breath and is found to have a hemoglobin of 7 with normal

MCV. His rectal exam shows no occult blood. What diagnosis should be consid-

ered, and how would you confirm the diagnosis?

G6PD deficiency with hemolysis following exposure to sulfonamide. Diagnose

using hemolysis labs (elevated lactate dehydrogenase [LDH], elevated indirect

bilirubin, decreased haptoglobin), G6PD enzyme level, and peripheral smear

showing Heinz bodies.

ANEMIA

Hemoglobin< 12 g/dL in women and < 14 g/dL in men. The MCV is used
to classify anemia (see Table 9.1).

SYMPTOMS/EXAM

■ Depends on chronicity and extent of anemia
■ Palpitations, dizziness, fatigue, orthostasis
■ Pale, tachycardia, hyperdynamic precordium, syncope

DIAGNOSIS

■ CBC with indices, reticulocyte count, peripheral smear

Microcytic anemias—

FALTS

Fe deficiency

Anemia of chronic

disease (may also be

normocytic)

Lead poisoning

Thalassemia

Sideroblastic anemia