Improved potassium reliability in whole blood through hemolysis detection on the novel GEM Premier 7000 blood gas analyzer

Hemolysis detection on GEM Premier 7000

  • Giuseppe Lippi
  • Dr. Laura Pighi Section of Clinical Biochemistry, University of Verona, Verona, Italy
  • Prof. Gian Luca Salvagno Section of Clinical Biochemistry, University of Verona, Verona, Italy
  • Dr. Filippo Marcazzan Section of Clinical Biochemistry, University of Verona, Verona, Italy
  • Dr. Mariateresa Rizza Section of Clinical Biochemistry, University of Verona, Verona, Italy
DOI: https://doi.org/10.5937/jomb0-58604
Keywords: hemolysis, blood gas analysis, point of care testing, preanalytical variability

Abstract


Background: Hemolysis is the most frequent preanalytical error in clinical laboratories, but its detection in point-of-care (POC) settings remains challenging due to the lack of sample separation. This study was planned to validate the hemolysis index (HI) threshold of GEM Premier 7000 blood gas analyzer for detecting hemolysis levels that may generate clinically significant interference in potassium measurement.

Methods: Heparinized whole blood samples were collected from healthy volunteers and divided into six aliquots; one was used as non-hemolyzed control, while hemolysis was mechanically induced in the remaining five aliquots by repeated aspirations through a fine-gauge needle. HI and potassium were measured on GEM Premier 7000.

Results: The final study population consisted in 18 volunteers. Both HI and potassium levels increased progressively and significantly with the number of fine-needle aspirations (p<0.001 for both). A strong positive correlation was observed between HI values and percentage increases in potassium concentration in hemolyzed aliquots (r=0.985, p<0.001). Receiver operating characteristic (ROC) curve analysis confirmed excellent diagnostic accuracy of HI in detecting potassium increases above the total 7.4% allowable error threshold, with an area under the curve (AUC) of 1.00 and optimal cutoff of 102 mg/dL (0.94 sensitivity and 1.00 specificity). At the manufacturer-recommended 116 mg/dL threshold, the AUC was 0.95, with 0.89 sensitivity and 1.00 specificity.

Conclusions: These results confirm that the novel GEM Premier 7000 blood gas analyzer provides accurate detection of hemolysis thresholds in whole blood that may impair potassium test reliability.

References

1. Lippi G, von Meyer A, Cadamuro J, Simundic AM. Blood sample quality. Diagnosis (Berl) 2019;6:25-31.
2. Simundic AM, Baird G, Cadamuro J, Costelloe SJ, Lippi G. Managing hemolyzed samples in clinical laboratories. Crit Rev Clin Lab Sci 2020;57:1-21.
3. Lippi G, Fontana R, Avanzini P, Sandei F, Ippolito L. Influence of spurious hemolysis on blood gas analysis. Clin Chem Lab Med 2013;51:1651-4.
4. Casati M, Intra J, Rossi W, Giacobone C, Brivio R. Hemolysis and blood gas analysis: it's time for a change! Scand J Clin Lab Invest 2022;82:138-42.
5. Buño A, Oliver P. POCT errors can lead to false potassium results. Adv Lab Med 2021;3:142-52.
6. Balasubramanian S, McDowell EJ, Laryea ET, Blankenstein G, Pamidi PVA, Winkler AM, et al. Novel In-Line Hemolysis Detection on a Blood Gas Analyzer and Impact on Whole Blood Potassium Results. Clin Chem 2024;70:1485-93.
7. Lippi G. Interference studies: focus on blood cell lysates preparation and testing. Clin Lab 2012;58:351-5.
8. European federation of Clinical Chemistry and Laboratory Medicine. EFLM Biological Variation Database. Available at: https://biologicalvariation.eu/. Last accessed, may 1, 2025.
9. Lippi G, Ippolito L, Fontana R. Prevalence of hemolytic specimens referred for arterial blood gas analysis. Clin Chem Lab Med 2011;49:931-2.
10. Salvagno GL, Lippi G, Gelati M, Guidi GC. Hemolysis, lipaemia and icterus in specimens for arterial blood gas analysis. Clin Biochem 2012;45:372-3.
11. Duhalde H, Skogö J, Karlsson M. Point-of-care hemolysis detection in blood gas specimens directly at the emergency department. Scand J Clin Lab Invest 2019;79:283-7.
12. Wilson A, Sweeney M, Mark Lynch PL, O'Kane MJ. Hemolysis Rates in Whole Blood Samples for Blood Gas/Electrolyte Analysis by Point-of-Care Testing. J Appl Lab Med 2018;3:144-5.
Published
2025/05/27
Issue
Vol. 44 No. 4 (2025): Journal of Medical Biochemistry
Section
Short Communication

Copyright (c) 2025 Giuseppe Lippi, Laura Pighi, Gian Luca Salvagno, Filippo Marcazzan, Mariateresa Rizza

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