Hypercalcemia is defined as serum calcium concentration two standard deviations above the mean values. Approximately half of the total serum calcium is bound to protein and the remaining free ionized calcium is physiologically active. Serum levels must be corrected to correlate with albumin levels before a diagnosis of hyper or hypocalcaemia is made.
Calcium (Ca) is essential for the formation of bones and teeth, and plays an integral role in neural transmission, enzyme activity, myocardial function, coagulation, normal muscle activity, and other cellular functions.
Regulation of plasma levels is by free exchange with body stores, and through the action of hormones such as calcitonin, parathyroid hormone and vitamin D, fibroblast growth factor 23 (FGF23) and phosphate.
Causes of Hypercalcaemia include
- Primary hyperparathyroidism
- Multiple myeloma
- vitamin D intoxification
- Lithium treatment
- periods of prolonged immobilisation
- acute renal injury
Causes of Hypocalcaemia include
- Inadequate Vitamin D
- Hypoparathyroidism post operatively or post radiotherapy
- Pseudohypoparathyroidism or pseudopseudohypoparathyroidism
- Hyper or hypomagnesemia
- Renal disease : excessive calcium excreted
- End-stage liver disease causing vitamin D inadequacy
- Bone disease – osteomalacia in adults or rickets in children
- Sclerotic metastases
- Genetic causes: congenital absence of parathyroid glands, Di George syndrome, or Fanconi syndrome
- Drugs (eg, rifampicin, antiepileptics, calcitonin, bisphosphonates, calcitonin, corticosteroids, chloroquine)
5mL venous serum or plasma
In addition to the packaging of samples, the transport/delivery of clinical samples to the laboratory is required to be in adherence to all national regulations for the safe transport of biological materials. Enfer Medical provides a fully compliant logistics service, aligned with clients’ testing requirements.
Prompt transport of specimens:
To ensure prompt testing of samples and release of results within the published test turnaround times, samples should arrive to the laboratory by 18:00. Test turnaround time is measured from receipt of the sample at the laboratory until the time the authorised results are reported to users.
In rare cases specimens may not be suitable for testing on arrival to the laboratory. In that case the sample will be rejected at the receipt stage and the service user will be notified immediately and an explanation as to why the sample could not be processed will be provided. Reasons why samples cannot be processed include but are not limited to:
- Samples received beyond the stability limits and/or not at the correct temperature indicated for each test.
- Incorrect sample type received.
- Leaking samples, sample not received or sample insufficient for analysis as stated below within sample requirements.
- Non-compliant samples or request forms i.e. those missing sample date information, missing sample test request and/or missing sample site/type information.
- Samples received without the necessary patient identifiers.
Quantitative results for Calcium are reported in Numeric value in mmol/L. Please contact us for more information on the reference ranges used at Enfer Medical.