Serum calcium and medicinal hypocalcemia

Anatori Sealife Comments 0 11th April 2019
SERUM CALCIUM and medicinal hypocalcemia

Serum calcium makes it possible to evaluate the disorder of calcium metabolism. Besides, an increase in concentration can establish malignant tumours. Also, osteolysis results from the release of peptides with action similar to the effect of the thyrotropic hormone. Primary hyperfunction of parathyroid glands, overdosage of D vitamin, myeloma and chronic enteritis (IVth stage) also impact adversely.

Medicinal hypocalcemia

Decrease of serum calcium concentration is possible at

  • hypo-activity of parathyroid glands (after surgical interventions, aplasia of parathyroid glands, auto immunisation).
  • Secondary hyper-function of parathyroid glands (insufficiency of D vitamin or resistance to it, chronic renal failure).
  • And sequestration of calcium ions (acute alkalosis, phosphates rise, abundant transfusion of citrated blood).
  • Osteomalacia of hypoalbuminemia, medicinal hypocalcemia (while receiving calcitonin, ethylene-diamine-tetraacetic acid, citrus, neomycin, fenobarbitalum).

Characteristics of hypocalcemia

Below-normal serum calcium concentrations of 8.5-10.5 mg/dl (2.1-2.5 mmol / l characterise hypocalcemia. The introduction into clinical practice of routine biochemical studies has contributed to improving the diagnosis of disorders of calcium metabolism, predominantly asymptomatic hypercalcemia. Even though, on the whole, hypocalcemia is less common in ambulatory patients, it can occur more often in patients with malignant neoplasms and kidney diseases than hypercalcemia.

Our body maintains the serum calcium concentration within 2.2-2.6 mmol / l. However, ionised or protein-unbound calcium is slightly less than half of the total calcium. Ionised calcium, a physiologically active fraction, participates in many diverse metabolic processes. Significant changes in serum protein concentration, essentially albumin, disrupt whole serum calcium level. A simple way to correct the results of determining calcium in the blood is to increase the calcium concentration by 0.25 mmol / L while decreasing the serum albumin concentration for every 10 g / L relative to the norm. Profound disturbances of calcium protein binding occur under the influence of changes in blood pH: an increase in pH leads to an increase in binding and, consequently, a decrease in the content of ionised calcium. This law explains the occurrence of symptoms of hypocalcemia in hyperventilating respiratory alkalosis.