Based on clinical presentation, but may include:
CBC (assess for significant anemia)
Reticulocyte count (<0.5% suggests aplastic crisis - rare in adults), calculating reticulocyte index
Laboratory value is a percentage, and absolute count corrects for level of anemia
Absolute retic count = % retics x (pt Hct / normal Hct)
Retic index = absolute retic count / maturation factor
≥35%, maturation factor 1.0
25 to <35%, maturation factor 1.5
20 to <25%, maturation factor 2.0
<20%, maturation factor 2.5
Reticulocyte index ≥2 means adequate response
Reticulocyte index <2 suggests hypoproliferation
Metabolic panel, lipase (if abdominal pain)
CXR (if cough, shortness of breath, or fever)
ECG
VBG
Urinalysis
Pregnancy test
CT brain (if symptoms of CVA)
Note that if patient is anemic, CT non-contrast is unreliable in ruling out hemorrhagic stroke, subarachnoid hemorrhage
Will need CTA, MRI, and/or MRA
Laboratory value is a percentage, and absolute count corrects for level of anemia
Absolute retic count = % retics x (pt Hct / normal Hct)
Retic index = absolute retic count / maturation factor
≥35%, maturation factor 1.0
25 to <35%, maturation factor 1.5
20 to <25%, maturation factor 2.0
<20%, maturation factor 2.5
Reticulocyte index ≥2 means adequate response
Reticulocyte index <2 suggests hypoproliferation
≥35%, maturation factor 1.0
25 to <35%, maturation factor 1.5
20 to <25%, maturation factor 2.0
<20%, maturation factor 2.5
Note that if patient is anemic, CT non-contrast is unreliable in ruling out hemorrhagic stroke, subarachnoid hemorrhage
Will need CTA, MRI, and/or MRA
Generally a clinical diagnosis
Certain syndromes require imaging/labs for confirmation (see below)
Sickle cell crisis
Vaso-occlusive pain crisis
Aplastic crisis
Bony infarction
Dialysis disequilibrium syndrome
Dactylitis
Hemolytic uremic syndrome
Avascular necrosis of femoral head