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Hypocalcemic crisis in children
Medical expert of the article
Causes of hypocalcemic crisis
Hypocalcemic crisis may be a consequence of hypothyroidism of parathyroid glands in idiopathic hypoparathyroidism or consequence of impaired parathyroid gland development (isolated agenesis or paresis of the parathyroid gland, Di Gheorghe syndrome). Surgical operations, radioiodine therapy of thyroid gland diseases, malignant or granulomatous diseases and degenerative processes of parathyroid glands also have a significant significance. This complication is accompanied by an autoimmune lesion of parathyroid glands, observed with hemochromatosis, thalassemia, Wilson's disease. The cause may be a lack of secretion of parathyroid hormone, and a deficiency of the calcium-sensitive receptor gene or hypomagnesemia. In newborns, hypocalcemia is idiopathic or mediated by maternal hyperparathyroidism, diabetes mellitus, asphyxiation and prematurity.
Hypocalcemia sometimes occurs in the case of hypersecretion of the parathyroid hormone: if resistance develops to it or the secretion of biologically inactive parathyroid hormone occurs. The causes of hypocalcemia may also be conditions after treatment of Paget's disease and after treatment of diffuse toxic goiter, successful rickets therapy, metastases of osteoblastic tumors (breast and prostate cancer), vitamin D deficiency (violation of 25-hydroxylation, l-alpha hydroxylation, enterohepatic regulation, alimentary deficiency, lack of ultraviolet radiation). Hypocalcemia also accompanies such diseases as malabsorption, steatorrhea, vomiting and diarrhea, short bowel syndrome, acute pancreatitis, alcoholism, chronic renal insufficiency.
In addition, hypocalcemia is of iatrogenic nature: with the introduction of phosphates (or as a consequence of their excess in food), ethylenediaminetetraacetic acid (EDTA), thiazide diuretics, the use of actinomycin, neomycin, laxatives, phenobarbital and other anticonvulsants, inhibitors of bone resorption (calcitonin, bisphosphonates), with massive transfusion of citrated blood, operations in conditions of extracorporeal circulation.
Symptoms of hypocalcemic crisis
The main symptom of hypocalcemia, regardless of its cause, is an increase in neuromuscular excitability and tonic convulsions. In newborns and young children, hypocalcemia is often asymptomatic, but in some cases, signs of hyperexcitability are revealed: tremor of the chin, limbs, muscle twitchings, clonus of the feet, shrill scream. Laryngospasm is possible. Respiratory disorders (tachypnea, episodes of apnea, inspiratory stridor), bloating, vomiting, muscle hypotension.
Early symptoms: paresthesia, "tingling" of the lips and at the fingertips, twitching or drawing pains in the muscles. Typical convulsive contractions of the muscles of the forearm and hand ("hand of the obstetrician"), stop ("horse stop"). Severe hypocalcemia leads to a violation of the heart rate and a decrease in blood pressure. In relatively mild cases, convulsions are often provoked by factors leading to a shift of CBS toward alkalosis, hyperventilation (crying, crying, physical exertion, hyperthermia), diuretics, vomiting. The severity of clinical manifestations of tetany significantly depends on the rate of hypocalcemia than on the degree of calcium loss in the blood.
Criteria for diagnosis
Hypocalcemia is recorded if the level of total calcium in the blood of full-term newborns and older children is below 2 mmol / L (ionized calcium is below 0.75-0.87 mmol / L), and in preterm infants - below 1.75 mmol / L (ionized calcium is below 0.62-0.75 mmol / l).
Emergency medical events
At the onset of tetany, calcium salts are administered in a dose of 10-20 mg / kg in terms of calcium, or 10-15 ml of a 10% solution of calcium chloride or calcium gluconate - intravenously strontaneously slowly under the control of the pulse (administration is discontinued with bradycardia). Further it is better to apply 1% solution 2-3 times a day or to enter calcium gluconate through a catheter into the central vein of a dropwise in a 0.9% solution of sodium chloride or in a 5% solution of glucose. If necessary, intravenous calcium supplementation can be repeated every 6-8 hours. Calcium preparations are then given intravenously at a dose of 50 mg / kghs (milk). If symptoms of latent tetany persist, 25% solution of magnesium sulfate in a dose of 0.2-0.5 ml / kg is injected intravenously.
Essential medicines for maintenance therapy during the interictal period are various forms of vitamin D and calcium preparations. Calcium carbonate is preferred, as well as its combined soluble salts in a daily dose of 1-2 g (element). It should be borne in mind that an excess of protein foods rich in phosphorus (meat, eggs, liver) can provoke a hypocalcemic crisis.