Hemoglobin and Hematocrit Increase Concerns

Primary Concerns

Red blood cell transfusions and resulting rapid increases in Hb/Hct have been associated with increased risks of venous thromboembolism (odds ratio 1.60) and arterial thromboembolism (odds ratio 1.53) 1

Determine if the elevation represents true polycythemia (actual increase in red cell mass) or apparent polycythemia (decreased plasma volume) 2
For true polycythemia, distinguish between primary polycythemia vera (clonal disorder) and secondary polycythemia (often EPO-mediated) 2

Repeated Hb/Hct measurements are essential as initial values in the normal range may mask early-phase bleeding 3
If the increase in Hct exceeds 8 percentage points per month (or Hb increase >3 g/dL per month), consider reducing EPO dosing by 25% if the patient is on such therapy 4

If the increase is due to transfusion, be aware that RBC transfusions have been associated with increased mortality (odds ratio 1.34), particularly with units stored for more than 14 days 1, 5
The major benefit of transfusion is rapid increase in Hb/Hct levels, with 1 unit of PRBCs typically increasing Hb by 1 g/dL or Hct by 3% 1

Despite traditional practice of maintaining higher Hb levels (approximately 10 g/dL) in TBI patients, evidence suggests this approach does not improve outcomes 5, 6
RBC transfusions in TBI patients have been associated with two-fold increased mortality and three-fold increased complication rates 6
Increasing Hct above 28% during the initial unstable phase following severe TBI has not been associated with improved outcomes 6
For CKD patients on erythropoietin therapy, the target Hb range should be 11-12 g/dL (Hct 33-36%) 7
Rapid increases in Hb/Hct with erythropoietin therapy require dose adjustment to prevent complications 4