Investigation and management of hypocalcaemia

Abstract

Hypocalcaemia is a common clinical scenario in children with a range of aetiological causes. It will often present with common symptoms but may occasionally be identified in an asymptomatic child. An understanding of the physiological regulation of plasma calcium is important in understanding the potential cause of hypocalcaemia and its appropriate management. The age of presentation will influence the likely differential diagnosis. We have presented a stepwise approach to the investigation of hypocalcaemia dependent on the circulating serum parathyroid hormone level at the time of presentation. The acute and long-term management of the underlying condition is also reviewed.

Epileptic seizures and abnormal tooth development as primary presentation of pseudohypoparathyroidism type 1B

“…The diagnostic workup of hypocalcaemia starts with distinguishing aetiology with a high versus low PTH secretion since the regulation of PTH is extremely sensitive for small changes in blood calcium level through the calcium-sensing receptor (CaSR). Secondly alkaline phosphatase and blood phosphate, as well as magnesium level, renal function and 25-hydroxy vitamin D3 need to be measured before starting the calcium supplementation 2. Measurement of phosphate is preferably done on a fasting sample since it has a circadian variability and is influenced by food intake 14.…”

“…Hypocalcaemia is defined as a serum calcium corrected for albumin <2.2 mmol/L or an ionised calcium<1.1 mmol/L 2. In this case, the hypocalcaemia was accompanied by an elevated PTH, reflecting a normal response of the parathyroids to the low serum calcium.…”

Hypocalcemia as a Cause of Complex Febrile Seizures in a Toddler

“…After pseudohypocalcemia, which is a low serum but normal ionized calcium, has been ruled out, additional blood samples should be collected for the analyses as given in Table 3, ideally prior to treatment initiation. Generally, a disorder in calcium metabolism can be identified using a limited number of analyses [7,9].…”

Endocrine Diseases of Newborn: Epidemiology, Pathogenesis, Therapeutic Options, and Outcome “Current Insights Into Disorders of Calcium and Phosphate in the Newborn”

“…The causes of neonatal hypocalcaemia are summarised in Table 1. Parathyroid glands can take >48 h to become responsive to the fetal-to-neonatal transition and important causes of hypocalcaemia can be helpfully thought of as early onset (<72 postnatal hours), or late onset (>72 postnatal hours) (31)(32)(33). Several genetic mutations have been found to cause Primary Hypoparathyroidism and should be considered when hypocalcaemia lasts >72 h. Isolated causes of hypoparathyroidism include GMC2 or PTH-gene mutations, autosomal dominant activating CASR or GNA11 mutations, and X-linked SOX3 mutations (8).…”