Approach To Ddx Of Elevated Hemoglobin

Question 1

Next step/s if there is Increased hct or hgb

Answer 1

Measure RBC mass
Measure serum EPO

Question 2

If RBC mass is elevated, what do you do next?

Answer 2

Measure serum EPO levels

Question 3

Elevated serum EPO levels, what to do next?

Answer 3

Measure arterial O2 saturation

Question 4

Measured arterial O2 saturation is normal, next step?

Answer 4

Smoker? Measure Carboxyhgb

Non smoker? Measure Hgb O2 affinity

Question 5

Smoker and elevated carboxyhemoglobin levels, dx is?

Answer 5

SMOKER’S POLYCYTHEMIA

Question 6

Inc hct or hgb and NORMAL RBC MASS

Answer 6

Dx: Relative erythrocytosis

Question 7

Elevated RBC mass and LOW EPO

Answer 7

Dx: Polycythemia vera

Confirm JAK 2 mutation

Question 8

Dx: Polycythemia vera

Answer 8

Confirm JAK2 mutation

Question 9

Increased hemoglobin 02 affinity

Answer 9

Dx: inc O2affinity Hemoglobinopathy

Question 10

Non smoker or normal Carboxyhgb and Normal hemoglobin 02 affinity

Answer 10

Search for tumor as source of EPI
Renal UTZ (Renal Ca or cyst)
Ct of head (Cerebellar Hemangioma)
CT of pelvus (uterine leiomyoma)
Ct of abdomen (hepatoma)

Question 11

Workup for epo tumor source

Answer 11

Search for tumor as source of EPO

• renal ultrasound (renal Ca or cyst)
• CT of head (cerebellar hemangioma)
• CT of pelvis (uterine leiomyoma)
• CT of abdomen (hepatoma)

Question 12

Elevated EPO and Low Arterial O2 saturation, what is the next step?

Answer 12

Diagnostic Evaluation for Heart or Lung disease, eg copd, high altitude, AV or intracardiac shunt