Original scientific paper

https://doi.org/10.11613/BM.2019.010709

Improving home haemodialysis: Stability evaluation of routine clinical chemistry analytes in blood samples of haemodialysis patients

Lourens J.P. Nonkes ; Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands
Maaike K. van Gelder ; Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
Hans Kemperman ; Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands
Alferso C. Abrahams ; Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands
Frans T.J. Boereboom ; Diakonessenhuis, Utrecht, The Netherlands and Dianet Dialysis Center, Utrecht, The Netherlands
Maarten J. ten Berg ; Department of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands
Karin G.F. Gerritsen ; Department of Nephrology and Hypertension, University Medical Center Utrecht, Utrecht, The Netherlands

Abstract

Introduction: A growing number of dialysis patients is treated with home haemodialysis. Our current pre-analytical protocols require patients to
centrifuge the blood sample and transfer the plasma into a new tube at home. This procedure is prone to errors and precludes accurate bicarbonate
measurement, required for determining dialysate bicarbonate concentration and maintaining acid-base status. We therefore evaluated whether
cooled overnight storage of gel separated plasma is an acceptable alternative.
Materials and methods: Venous blood of 34 haemodialysis patients was collected in 2 lithium heparin blood collection tubes with gel separator
(LH PSTTM II, REF 367374; Becton Dickinson, New Jersey, USA). One tube was analysed directly for measurement of bicarbonate, potassium, calcium,
phosphate, glucose, urea, lactate, aspartate aminotransferase (AST), and lactate dehydrogenase (LD); whereas the other was centrifuged and stored
unopened at 4 °C and analysed 24 h later. To measure analyte stability after 24 h of storage, the mean difference was calculated and compared to the
total allowable error (TEa) which was used as acceptance limit.
Results: Potassium (Z = - 4.28, P < 0.001), phosphate (Z = - 3.26, P = 0.001), lactate (Z = - 5.11, P < 0.001) and AST (Z = - 2.71, P = 0.007) concentrations
were higher, whereas glucose (Z = 4.00, P < 0.001) and LD (Z = 3.13, P = 0.002) showed a reduction. All mean differences were smaller than
the TEa and thus not clinically relevant. Bicarbonate (Z = 0.69, P = 0.491), calcium (Z = - 0.23, P = 0.815) and urea (Z = 0.81, P =0.415) concentrations
were stable.
Conclusions: Our less complex, user-friendly pre-analytical procedure resulted in at least 24 h stability of analytes relevant for monitoring haemodialysis,
including bicarbonate. This allows shipment and analysis the next day.

Keywords

haemodialysis; clinical chemistry tests; bicarbonates; blood specimen collection

Hrčak ID:

217222

URI

https://hrcak.srce.hr/217222

Publication date:

15.2.2019.

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