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patients follow an indolent course presenting with symptoms evolving over days or
weeks. Any unexplained low hemoglobin level, typically accompanied by a
reticulocytosis, should prompt consideration of a hemolytic anemia.
Triage
Children with hemolytic anemia often present in a relatively compensated state;
however, their clinical status can deteriorate rapidly. Severe, uncontrolled hemolytic
anemia can be fatal with patients succumbing to insufficient oxygen-carrying capacity
and cardiovascular collapse. Ongoing assessment of cardiovascular and neurologic
status is crucial during the diagnostic evaluation and until the rate of hemolysis is
controlled. Hematology and the blood bank should be consulted early for patients with
suspected hemolytic anemia.
Initial Assessment/H&P
The history should focus on systemic complaints relevant to anemia and hemolysis such
as fatigue, light-headedness or near-syncope, fussiness, irritability or feeding difficulties
in young children, and dyspnea. Probe for symptoms of a systemic autoimmune process,
an immunologic disorder, or malignancy as these can be associated with AIHA. Elicit
any personal or family history of an intrinsic RBC defect or AIHA. Attention to recent
exposures including symptoms suggestive of a recent or concurrent viral illness, toxins
(e.g., naphthalene-containing mothballs), and medications can also provide clues about
possible triggers ( Table 93.3 ). Typical examination findings for patients with
hemolytic anemia include jaundice/icterus, pallor, tachycardia in some cases
accompanied by murmur from a high-output cardiac state, and mild
hepatosplenomegaly. Other findings such as lymphadenopathy or massive
hepatosplenomegaly may suggest underlying infection or malignancy. The presence of
jugular venous distention, significant hepatosplenomegaly, gallop rhythm, respiratory
distress, hypotension, or poor perfusion heralds imminent cardiovascular collapse.
Diagnostic Testing
A basic approach to the evaluation of hemolytic anemia is presented in Figure 93.2 .
The initial laboratory evaluation should include a CBC and differential, peripheral blood
smear, reticulocyte count, blood type and antibody screen (indirect antibody test, also
known as an indirect Coombs test), direct antiglobulin test (DAT, also called a direct

Coombs test), haptoglobin, serum electrolytes, BUN/Cr, and bilirubin level. The goals
are to identify a hemolytic anemia, prepare for transfusion in case the hemoglobin is
critically low or falling rapidly, and narrow the differential of the causative mechanism.
Reticulocytosis is present in most cases but can be absent or delayed in up to 10% of
patients. Therefore, consideration of hemolytic anemia should not be eliminated based
solely on a low reticulocyte count. Distinguishing between an immune- and a non–
immune-mediated hemolytic anemia is an essential first step to guide therapy. The DAT
uses broad-spectrum Coombs serum (IgG, IgM, and complement) to detect the presence