LQPB2602 - CMLE - Extremely Elevated Hemoglobin and Hematocrit Results from a Healthy 41-Year-Old Woman-Extremely Elevated Hemoglobin and Hematocrit Results from a Healthy 41-Year-Old Woman

Extremely Elevated Hemoglobin and Hematocrit Results from a Healthy 41-Year-Old Woman

Pdf Summary

This phlebotomy case-based module explains how pre-analytical errors—responsible for most laboratory testing mistakes—can cause unexpected hematology and chemistry results. A healthy 41-year-old potential kidney donor had critically high hemoglobin and hematocrit results despite normal chemistry findings; repeat analysis on the same tube reproduced the abnormal values, suggesting a non-analytical problem.<br /><br />Investigation focused on the pre-analytical phase (collection through processing). Labeling was correct, but visual comparison of concurrently drawn tubes showed the EDTA hematology tube had reduced plasma volume and a disproportionately large red cell layer compared with the blood bank EDTA tube. The root cause was improper specimen processing: after accessioning, a large amount of plasma was aliquoted from the hematology tube for send-out testing before the CBC was performed. The tube was then remixed and used for CBC, violating standard procedure. Removing plasma from whole blood falsely increases hematocrit (a red cell volume/total blood volume ratio) and can distort related parameters. When the blood bank tube (not plasma-reduced) was tested, hemoglobin and hematocrit were normal, clearing the patient as a donor.<br /><br />The document reviews common pre-analytical errors (clots, hemolysis, insufficient volume, mislabeling, contamination, wrong tube, and improper storage/transport), emphasizes correct tube selection (eg, EDTA for CBC; citrate for coagulation; heparin unsuitable for PCR), and highlights handling requirements (order of draw to prevent additive carryover, prompt processing to prevent potassium/glucose artifacts). It also outlines specimen stability considerations and cautions about add-on testing to stored or previously processed samples, especially that hematology testing requires intact anticoagulated whole blood and becomes unreliable after plasma removal or chemistry processing. Team communication, nonpunitive error reporting, and quality monitoring are emphasized to prevent recurrence.

Keywords

pre-analytical errors

phlebotomy specimen processing

CBC EDTA tube

plasma aliquoting artifact

falsely elevated hematocrit

hemoglobin discrepancy investigation

order of draw additive carryover

specimen stability and transport

add-on testing limitations

laboratory quality improvement and error reporting