Biochemia Medica, Vol. 30 No. 2, 2020.
Other
https://doi.org/10.11613/BM.2020.021001
Case report of spuriously low sodium and calcium in a 36-year-old male in primary care
Seán J. Costelloe
; Department of Clinical Biochemistry, Cork University Hospital, Wilton, Cork, Republic of Ireland
Kelly McCarthy
; Department of Clinical Biochemistry, Cork University Hospital, Wilton, Cork, Republic of Ireland
Marguerite O’Connell
; Department of Clinical Biochemistry, Cork University Hospital, Wilton, Cork, Republic of Ireland
Mark Butler
; Department of Clinical Biochemistry, Cork University Hospital, Wilton, Cork, Republic of Ireland
Abstract
An unseparated serum specimen for a 36-year-old male was received from primary care. The specimen arrived in the laboratory at Cork University
Hospital one day after collection, as documented on the paper request card, and was promptly centrifuged. Analysis was delayed for three days
due to operational constraints and serum indices were run at the same time as the biochemical analyses. Results showed a moderately haemolysed
specimen with remarkably low concentrations of both sodium (119 mmol/L) and total calcium (1.15 mmol/L), with all other parameters within their
appropriate reference intervals (RIs). The complete report was released electronically and both sodium and calcium results were phoned to, and
acknowledged by, the requesting general practitioner (GP). Discussion between the medical scientists and clinical biochemist on duty raised the
possibility that the specimen was significantly older than initially thought. Further discussion of results with the GP clarified that the documented
time of collection corresponded with specimen receipt by the courier, rather than the time of phlebotomy. Thus, the specimen was 7 days old when
received in the laboratory and 10 days old when analysed. This case illustrates the dangers of multiple convergent preanalytical errors. Laboratories
should be mindful of the stability of analytes in unseparated blood and unusual patterns of results which might suggest a specimen is “old”, and
that this may coexist with erroneous request information. Any potential adverse effects on patient care were prevented in this case by laboratory
vigilance.
Keywords
delayed separation; spurious hyponatraemia; spurious hypocalcaemia; haemolysis; case report
Hrčak ID:
238914
URI
Publication date:
15.6.2020.
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