Levels of Hemolysis

NIH for VADS

  NIH   ||    Clinical Outcomes
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  >0.06   ||    Increased levels of PfHb
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  >0.04   ||    No increase of PfHb but blood transfusion required
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  <0.04   ||    Physiologically acceptable --------------------------------------------------------------
  <0.02   ||    Clinically acceptable
  <0.01   ||    Design objective
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This is taken from "Design and development strategy for the Rotary blood pumps," Artificial Organs, 1998, 22(6):438 [also see -- ASTM F1841-97/F1830-97]

Normalized Index of Hemolysis

Normalized Index of Hemolysis (NIH) is the clinical measure of hemolysis as per the ASTM standards.
NIH (g/100L) = \delta_PfHb x V x [ (100-Hct)/Hct ] x [ 100 / (Q x T) ]
where:
a.   \delta_PfHb = increase in plasma free hemoglobin concentraion (g/L)
b.   V = volume of blood in mock loop circuit (L)
c.   Hct = hematocrit
d.   Q = flow rate (L/min)
e.   T = Time (min)
NIH can be stated as:
Amount of PfHb released per pass of blood volume through the blood pump.
The hemolysis ratio which is more commonly used in the simple shear hemolysis experiments can be converted to NIH as:
NIH (g/100L) = 100 x [\delta_Hb / Hb] x [1 - Hct/100] x k where:
a.   [\delta_Hb / Hb] = hemolysis ratio
b.   Hct = hematocrit
c.   k = hemoglobin content of blood (150g/L) for healthy person