Second fingerstick: a simple method to increase the blood supply.

Before blood donors are deferred because of a low hemoglobin determination by the copper sulfate procedure, they are routinely retested with a microhematocrit. The copper sulfate test and the microhematocrit usually are performed on blood samples taken from the same finger (or earlobe) puncture. We studied 201 male and female volunteer blood donors who failed the copper sulfate test to determine if more donors would be accepted for donation if blood from a second fingerpuncture, instead of the original fingerstick, was used for the microhematocrit determination. Venous blood samples were obtained to evaluate complete blood count and measures of iron status. The results indicated that the deferral rate was reduced by 46% using a fresh fingerpuncture for the microhematocrit determination. The iron status of the additional donors accepted on the basis of the second puncture was not significantly different from that of the donors accepted by the original fingerstick. We conclude that using a second fresh fingerpuncture for the microhematocrit determination after failing the copper sulfate test decreases the number of hematocrit deferrals and does not compromise the iron status of the additional donors.