Inaccuracy in automated measurement of hematocrit and corpuscular indices
in the presence of severe hyperglycemia
JA Strauchen, W Alston, J Anderson, Z Gustafson and LF Fajardo
Because we recently observed two patients with severe diabetic
hyperglycemia and spuriously elevated electronically determined hematocrit
and mean corpuscular volume (MCV), we investigated the effect of
hyperglycemia on two popular automated hematology systems, the Coulter S
and Ortho ELT-8. Marked hyperglycemia (blood glucose 800-- 2000 mg/dl)
caused consistent overestimation of the electronically determined MCV
compared to that derived from a simultaneous spun microhematocrit. The
resultant overestimation and underestimation, respectively, of the derived
values for hematocrit and mean corpuscular hemoglobin concentration may be
clinically misleading. The mechanism of MCV elevation in hyperglycemia
appears to be swelling of hyperosmolar glucose "loaded" erythrocytes when
diluted into "isotonic" counting medium. This effect is readily
circumvented by determination of a spun microhematocrit.
Volume 57,
Issue 6,
pp. 1065-1067,
06/01/1981
Copyright © 1981 by The American Society of Hematology