Hemoglobin Determination in Blood Donors

Accuracy of predonation Hct sampling affects donor safety, eligibility, and deferral rates

“…To address this issue, we also compared predonation and postdonation venous results in a small group of donors. Consistent with other published reports, 9,10 we found that, during whole‐blood donation, Hct variably decreases by 0 to 4 units, with an average drop of 1.7 units. Given this approximate decrease of 2 Hct units during whole‐blood donation, the 6‐unit discrepancy reported here for predonation ES and postdonation venous Hct seems concordant with previous reports 4 .…”

Evidence‐based criteria for the care and selection of blood donors, with some comments on the relationship to blood supply, and emphasis on the management of donation‐induced iron depletion

“… Sample site – earlobe‐stick blood has higher Hb values than finger‐stick blood, which are generally closer to venous blood Hb (Chambers & McGuff, 1989); Variations between Hb from different fingers (often over 10% –Boulton, Nightingale & Reynolds, 1994); Limitations because of methodology and performance variables (Walters & Garrity, 2000). Reported differences between capillary (finger‐stick) and venous blood Hb (Vuk et al ., 1998; Neufeld et al , 2002; Darragh et al , 2006) may be unreliable because each sample‐type was analysed on different apparatus calibrated separately; Environmental conditions at blood donation sessions may be associated with less reliable staff performance (Boulton et al , 2001); Seasonal variation – Hb can decrease by 2 g L −1 in summer over winter in temperate climes (Hoekstra et al , 2007; Sebok et al , 2007); Ethnicity – as commented above for Afro‐Americans and South‐East Asians; Age – Hb declines in men after the eighth decade; and whereas in women it rises following the menopause, it also declines after the eighth decade (White et al , 1993); Other physiological factors – posture, diurnal rhythms, prandial, altitude (or smoking), menstrual cycle stage, BMI etc. White et al , 1993 found higher BMI to be associated with higher Hb; this may not wholly be simply an artefact through sampling from obese arms. …”

“…Limitations because of methodology and performance variables (Walters & Garrity, 2000). Reported differences between capillary (finger‐stick) and venous blood Hb (Vuk et al ., 1998; Neufeld et al , 2002; Darragh et al , 2006) may be unreliable because each sample‐type was analysed on different apparatus calibrated separately;…”