Heparin effect on ionised calcium concentration

A 76-year-old renal transplant patient due to autosomal dominant polycystic kidney disease who resumed chronic haemodialysis was admitted to our hospital for confusion and lassitude. He was afebrile and physical examination revealed diffuse bilateral rales with decreased respiratory sounds in lower right lung. Laboratory data showed hypercalcaemia (total calcium 3.92 mmol/L (normal range 2.2–2.6 mmol/L), ionised calcium 1.87 mmol/L (1.15–1.35 mmol/L)), low intact parathyroid hormone (iPTH) 15 ng/L, (15–65 ng/L) and high 1,25(OH)2D3 128.9 pg/mL, (15.2–90.1 pg/mL). Chest CT-scan revealed bilateral apical lung lesions after 15 days of antibiotics. Bronchoalveolar sample was PCR positive for Pneumocystis jirovecii. He was treated with an extra session of haemodialysis with 1.25 mmol/L dialysate calcium concentration, oral trimethoprim-sulfamethoxazole was started and oral corticosteroid dose increased to 1 mg/kg for 1 week. Hypercalcaemia decreased progressively after initiation of these treatments. We concluded a case of hypercalcaemia secondary to P. jirovecii infection.

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Parathyroid immunohistochemistry in a 12-year-old mixed-breed dog with parathyroid adenocarcinoma

Veterinary Record Case Reports ◽

10.1136/vetreccr-2018-000601 ◽

2018 ◽

Vol 6 (3) ◽

pp. e000601

Author(s):

Anna-Maria Kaiser ◽

Lena Kempker ◽

Reto Neiger

Keyword(s):

Parathyroid Hormone ◽

Parathyroid Gland ◽

Vascular Invasion ◽

Calcium Concentration ◽

Clinical Presentation ◽

Parathyroid Tissue ◽

Initial Presentation ◽

Positive Staining ◽

Mixed Breed ◽

Ionised Calcium

SummaryA 12-year-old, female, spayed, mixed-breed dog with acute lethargy, anorexia and weakness and markedly elevated total and ionised calcium concentration showed an enlarged left cranial parathyroid gland on ultrasonography of the ventral neck. Despite preoperative therapy with furosemide and calcitonin, there was no decline of plasma ionised calcium concentration. The dog deteriorated rapidly and was euthanased two days after initial presentation. Postmortem histopathology revealed parathyroid tissue with characteristics of malignancy as local and vascular invasion. Immunohistochemistry showed parathyroid hormone positive staining of these cells. Unusual clinical presentation and histopathological characteristics are discussed.

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Effect of blood ionised calcium concentration at calving on fertility outcomes in dairy cattle

Veterinary Record ◽

10.1136/vr.104932 ◽

2018 ◽

Vol 183 (8) ◽

pp. 263-263 ◽

Cited By ~ 2

Author(s):

Philippa Jane Mahen ◽

Helen J Williams ◽

Robert Frank Smith ◽

David Grove-White

Keyword(s):

Dairy Cattle ◽

Dairy Cow ◽

Calcium Concentration ◽

Point Of Care ◽

Dairy Herds ◽

Ionised Calcium ◽

Cattle Blood ◽

Multifactorial Approach ◽

Canada Data ◽

Subclinical Hypocalcaemia

Clinical and subclinical hypocalcaemia are common in dairy cows, yet evidence in the literature assessing their impact on fertility is inconsistent. The aim of this prospective cohort study was to examine associations between blood ionised calcium concentration at calving and fertility outcomes in dairy cattle. Blood samples were taken from 137 Holstein cows from four commercial dairy herds within 24 hours of calving and analysed for blood ionised calcium using an Epocal Point of Care Analyser (Epocal, Ottawa, Canada). Data collected from routine veterinary fertility examinations and herd records were used to investigate the association of ionised calcium with the outcomes: time to first service, time to conception and endometritis. There were significant negative associations between blood ionised calcium concentration and time to first service (HR 1.33, P=0.001) and blood ionised calcium concentration and time to conception (HR 1.16, P=0.04). There was no significant association between blood ionised calcium concentration and endometritis. The results of this study imply that management policies that minimise the reduction in blood ionised calcium concentration in the periparturient dairy cow are likely to improve reproductive outcomes and should be considered as part of the multifactorial approach to optimising dairy cow fertility.

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The Effects of Zero Magnesium Dialysate and Magnesium Supplements on Ionised Calcium Concentration in Patients on Regular Dialysis Treatment

Nephrology Dialysis Transplantation ◽

10.1093/oxfordjournals.ndt.a091572 ◽

1987 ◽

Keyword(s):

Calcium Concentration ◽

Dialysis Treatment ◽

Ionised Calcium ◽

Regular Dialysis Treatment

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Protein Interferes with Ionised Calcium Measurement at the Reference Electrode Liquid Junction

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/000456328702400409 ◽

1987 ◽

Vol 24 (4) ◽

pp. 400-407 ◽

Cited By ~ 11

Author(s):

R B Payne ◽

D P Jones

Keyword(s):

Protein Concentration ◽

Calcium Concentration ◽

Reference Electrode ◽

Liquid Junction ◽

Human Control ◽

Control Serum ◽

Ionised Calcium ◽

Clinically Significant ◽

Calcium Measurement ◽

Junction Potential

The ionised calcium concentration of sequential retentates prepared by ultrafiltration of a human control serum increased with increasing protein concentration when measured with both a Nova 2 and a Radiometer ICA1 analyser using their standard reference electrodes. In contrast, the ionised calcium in the same retentates fell slightly with increasing protein when the reference electrode liquid junctions of the instruments were changed from hypertonic to isotonic solutions, the values then paralleling those in the filtrates. Thus, the clinically significant positive relationship between ionised calcium and protein that has been reported with the Nova 2 and ICA1 analysers is almost certainly an effect of protein on the reference electrode liquid junction potential rather than a consequence of a Donnan effect on true ionised calcium distribution.

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Clinically Significant Effect of Protein Concentration on Ion-Selective Electrode Measurements of Ionised Calcium

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/000456328201900406 ◽

1982 ◽

Vol 19 (4) ◽

pp. 233-237 ◽

Cited By ~ 20

Author(s):

R B Payne

Keyword(s):

Plasma Proteins ◽

Protein Concentration ◽

Calcium Concentration ◽

Human Albumin ◽

Albumin Concentration ◽

Selective Electrode ◽

Serum Samples ◽

Ionised Calcium ◽

Clinically Significant ◽

Positive Interference

Others, using an Orion SS-20 ionised calcium analyser, noted that the ionised calcium concentration of a native serum sample was 8% greater than that of its ultrafiltrate. The experiments described here, using a Nova 2 ionised calcium analyser, confirmed a positive protein interference which was greater for human albumin than for IgG. Uncharged dextran showed no positive interference but dextran sulphate, which is highly charged and binds calcium, showed a large effect. Thus the interference is related to macromolecule charge. Dialysis experiments with normal and pathological human serum samples indicated that the ionised calcium of diffusible plasma water was overestimated by an average of 9 · 6% at an albumin concentration of 40 g/l and by 4 · 8 % at 20 g/l. It is concluded that the measurement of ionised calcium with existing analysers can be clinically misleading in patients with abnormal plasma proteins. Hypocalcaemia is likely to be overdiagnosed and hypercalcaemia underdiagnosed in the presence of hypoalbuminaemia.

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An Isotonic Potassium Chloride Liquid Junction Minimises the Effects of Ionic Strength, Protein and Haematocrit on Ionised Calcium Measurement

Annals of Clinical Biochemistry International Journal of Laboratory Medicine ◽

10.1177/000456328802500305 ◽

1988 ◽

Vol 25 (3) ◽

pp. 228-232 ◽

Cited By ~ 6

Author(s):

R B Payne

Keyword(s):

Ionic Strength ◽

Potassium Chloride ◽

Calcium Concentration ◽

Reference Electrode ◽

Sodium Formate ◽

Liquid Junction ◽

Ionised Calcium ◽

Isotonic Sodium Chloride ◽

Calcium Measurement ◽

Junction Potential

When the reference electrode liquid junction of a Nova 2 analyser was changed to isotonic potassium chloride, increasing the ionic strength of aqueous solutions containing a constant total calcium concentration had a negligible effect on measured ionised calcium. In contrast, measurements using hypertonic potassium chloride, hypertonic sodium formate and isotonic sodium chloride liquid junctions showed significant sample ionic strength effects. Interferences by sample protein concentration and haematocrit were marked with hypertonic, but negligible with isotonic junctions. Ionised calcium values in samples containing 25 mmol/L acetate, bicarbonate, β-hydroxybutyrate, lactate or pyruvate were all lower by 6–7% with an isotonic than a hypertonic potassium chloride junction. Thus, anions that replace bicarbonate during metabolic acidosis have a similar effect on residual liquid junction potential. The clinical usefulness of an isotonic potassium chloride liquid junction needs to be evaluated.

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