Unacceptable variability of hemoglobin estimation on samples obtained from ear punctures

Area of Science:

• Hematology
• Blood Donor Screening

Background:

• Accurate hemoglobin determination is crucial for blood donor eligibility.
• Capillary sampling methods, like finger and ear punctures, are commonly used for rapid screening.

Purpose of the Study:

• To compare the accuracy, precision, and impact on donor deferral rates of finger, ear, and venous blood sampling techniques for hemoglobin estimation.

Main Methods:

• Collected finger, ear, and venous blood samples from volunteers.
• Performed microhematocrit analysis on post-donation samples.
• Assessed donor deferral rates based on different sampling techniques.
• Investigated the effect of vigorous ear manipulation on hematocrit results.

Main Results:

• Ear puncture microhematocrits were 7% higher than finger or venous samples.
• Ear puncture samples showed lower accuracy and precision compared to finger punctures.
• Finger puncture screening excluded approximately 6% more donors than ear puncture screening.

Conclusions:

• Ear puncture sampling for hemoglobin estimation is less reliable than finger puncture.
• Differences in sampling techniques can significantly affect blood donor eligibility and deferral rates.