Hypercalcemia is a polytheological pathology that is observed as a symptomatic complex of other diseases or an independent nosological form, based on a sharp or moderate increase in the serum calcium concentration.
Due to the fact that this pathological condition belongs to the category of clinico-laboratory changes, the blood tests for the level of calcium saturation, as well as instrumental imaging methods (radiation diagnostic methods) are on the foreground as diagnostic measures.
The clinical picture of this pathology has a direct relationship with the degree of increase in calcium concentration and the age of the patient. The basis of therapeutic measures of hypercalcemia includes stimulation of calcium excretion from the body by conservative methods, as well as prevention of possible resorption of bone tissue.
Causes of hypercalcemia
The main link in the etiopathogenesis of hypercalcemia is the excessive destruction of the structure of the bone tissue of one or another localization that can occur in various pathologies (osteoclastic type of metastasis, thyroid pathology with severe hyperthyroidism , malignant neoplasms with concomitant humoral hypercalcemia, prolonged immobilization, hypocalcauroic hypercalcemia, hypervitaminosis of groups D and A).
Another common mechanism for the development of hypercalcemia is an increase in the absorption of calcium in the jejunum, which is observed in the lactic-alkaline syndrome and sarcoidosis . Also, this mechanism of hypercalcemia is observed in patients taking long-term medicines containing calcium (antacids in diseases of the gastroenterological profile).
In addition to the above factors, the functioning of the urinary system is of great importance in the development of hypercalcemia. when the excretory process is suppressed, calcium retention in the blood is observed.
Symptoms and signs of hypercalcemia
Initially, hypercalcemia is characterized by latent flow, in which the patient does not have any painful sensations or the symptoms are so nonspecific that the patient can not recognize the cause of their occurrence. At this stage, this disease should be attributed to the category of random findings when conducting a screening laboratory examination of the patient.
More patients suffering from hypercalcemia of varying severity complain of various dyspeptic disorders (nausea, lack of appetite, heartburn). During the unfolded clinical picture, hypercalcemia manifests itself as symptoms of intestinal obstruction (prolonged constipation , flatulence, spastic pain syndrome in the projection of the abdominal cavity without clear localization). Due to the available reversible changes in renal concentrating mechanisms, the patient may experience polydipsia, nocturia and polyuria, which are of a transient, transient nature.
In a situation where the patient has hypercalcemia with a significant increase in calcium concentration in the body, severe clinical symptoms develop, which requires urgent medical intervention. The patient becomes emotionally labile, and in a far-reaching stage, various degrees of impairment of consciousness from somnobulence to coma are noted. The patient is disturbed by generalized muscle weakness, inability to perform the usual physical activity, however, convulsive syndrome with this pathology is extremely rare.
Prolonged hypercalcemia is always accompanied by transient or chronic renal failure, caused by the formation of many microcalcinates in the thickness of the renal parenchyma. It should be remembered that the violation of the urinary function of the kidneys provokes the development of a persistent malignant hypertension in a patient with hypercalcemia, which in some cases is the only clinical manifestation of this disease.
If hypercalcemia occurs against a background of hyperparathyroidism , the patient has a tendency to develop peptic ulcers and signs of acute pancreatitis . Prolonged severe hyperthyroidism is accompanied by the development of generalized fibrous osteodystrophy, which is characterized by an increase in the activity of osteoclasts and, as a consequence, the formation of areas of fibrous degeneration and cystic bone restructuring of various localizations. The risk category for this pathology is patients with renal failure who are on continuous dialysis, as well as patients with a secondary form of hyperparathyroidism. Laboratory confirmation of fibrotic osteodystrophy is a significant increase in the serum of the alkaline phosphatase index.
Statistical data prove the possibility of a lethal outcome in hypercalcemia. The fatal outcome comes with the development of shock and acute renal failure.
Hypercalcemia in children
Hypercalcemia refers to one of the forms of disturbed mineral metabolism and the frequency of occurrence of this pathology is much lower in comparison with hypocalcemia, but despite this fact, this pathology in childhood always runs hard and needs immediate medical correction.
The appearance of certain clinical manifestations in hypercalcemia depends on the age of the patient and the degree of increase in the saturation of blood serum with calcium. Different age categories are characterized by the development of various forms of this pathology, which are fundamentally different in the nature of the onset of hypercalcemia and, accordingly, approaches to its treatment.
Thus, the period of newborns is considered critical for the development of Williams syndrome , which in pediatrics is called "idiopathic hypercalcemia". The cause of this pathology is a congenital genetic mutation, and the main pathogenetic mechanism of hypercalcemia is the enhancement of calcium absorption in the small intestine.
Considering the experience of long-term follow-up of patients suffering from idiopathic hypercalcemia, a classical triad of clinical signs was identified: a sharp lag in mental development, gross vascular anomalies and a change in the facial part of the skull with the formation of a phenotypic "elf face". Over time, children suffering from this form of hypercalcemia are more likely to develop cognitive and intellectual disorders.
Unfortunately, at present, it has not been possible to develop diagnostic methods for determining the signs of Williams syndrome in the prenatal period. The main therapeutic measures for this pathology are the restriction of daily calcium intake by the child, as well as observance of the specific dietary nutrition of the mother during lactation, control of the dosing of the vitamin D solution, and only the administration of glucocorticosteroid therapy (hydrocortisone in a daily dose of 10 mg per 1 kg weight of the child).
Also, the congenital form of hypercalcemia includes the family heterozygous type, which is characterized by a benign course and the absence of specific clinical signs allowing early diagnosis of this pathological condition.
Family hypercalcemia is most often an accidental finding in a planned screening laboratory examination of a child and does not require the use of medication.
Hypocalcauroic hypercalcemia belongs to the category of urgent conditions requiring immediate medication, since this pathology is characterized by a rapidly progressive aggressive course. The manifestations of this form of hypercalcemia are observed immediately after the birth of the child, and consist in the development of gross congenital anomalies of the skeleton, a sharp delay in the physical and mental development of the newborn. In addition to the critically high level of calcium in the serum, the biochemical laboratory criteria of this pathology include an increase in the concentration of parathyroid hormone and a significant decrease in the level of calcium in the urine. In view of the fact that hypocalciuric hypercalcemia in most cases has an unfavorable outcome, children immediately after birth are recommended to perform removal of parathyroid glands with simultaneous autotransplantation of parathyroid tissue in the muscular forearm massif. Long-term rehabilitation treatment consists in the use of calcium-containing drugs and vitamin D solution.
Nonspecific form of hypercalcemia, which is observed in both adult patients and children, is immobilization. This pathology develops as a result of demineralization of bone tissue in areas that are long in immobilized position with severe polytrauma or burn injury. In this regard, the most effective way to prevent the development of signs of hypercalcemia in this group of patients is their activation in the early rehabilitation period. With the available signs of immobilization hypercalcemia, an adequate scheme of diuretic therapy (Furosemide at a calculated dose of 1 mg / 1 kg of the child's weight intravenously) has a good effect.
If the intake of synthetic preparations of vitamin D is not observed, which is used both as a preventive and therapeutic agent in the breast period, conditions for the development of signs of hypercalcemia are created. In this situation, the initial measures are the immediate cessation of taking the drug containing vitamin D, as well as the correction of the child's eating behavior, implying abstinence from eating foods that contain calcium.
Treatment of hypercalcemia
The volume of necessary medical measures directly depends on the degree of concentration of serum calcium, as well as on the existing background disease, which became the primary cause of hypercalcemia.
The diet for hypercalcemia is classified as a minor conservative treatment and must be supplemented with medications in a severe situation.
In the case when the patient shows a sharp increase in the concentration of calcium in the blood serum, as well as in severe hypercalcaemia, it is necessary to urgently use medication correction methods.
When the patient does not show signs of impaired renal function, it is advisable to use intravenous infusion of sodium chloride, the action of which is aimed at stimulation of calciuria. Effective is an infusion, in which the volume of daily diuresis is at least three liters. After the introduction of 0.9% sodium chloride in a volume of two liters, it is necessary to stimulate diuresis using diuretic drugs (Furosemide in a dose of 80 mg parenterally at a frequency of every 8 hours and a duration of at least 2 days). An obligatory component of the scheme of diuretic therapy is the use of potassium chloride drugs, the action of which is aimed at preventing possible hypokalemia .
In a situation where a severe form of hypercalcemia is observed in patients on the background of existing renal failure, the maximum and fastest effect is the method of hemodialysis, implying the use of solutions containing calcium in minimal amounts. The drug of choice in this situation is a solution of potassium and sodium phosphate, which in the volume of one dose with the intravenous method of administration allows eliminating manifestations of hypercalcemia for two weeks. This technique should be used with caution, as it has a number of adverse reactions, among which the most common is the formation of calcifications in soft tissues, especially at injection sites.
Patients with hypercalcemia of paraneoplastic genesis are recommended to use Mithramycin in a daily dosage of 25 mg / kg of weight of the patient by intravenous administration. But it should be taken into account that this drug belongs to the category of highly toxic pharmacological preparations, therefore it is necessary to dose the injected drug with particular care.
In the treatment of chronic form of hypercalcemia, salmon calcitonin should be preferred in a maximum daily dosage of 8 IU / 1 kg of patient weight subcutaneously or Prednisone in a daily dose of 60 mg orally. These drugs are used to stop severe paraneoplastic hypercalcemia, if the application of sodium chloride has not had the proper positive effect. Calcitonin analogue with greater efficacy in correcting hypercalcemia is Gallium Nitrate in a single dose of 200 mg, the duration of which in some cases exceeds 15 days. Due to the fact that this drug has a wide range of adverse reactions, including the development of signs of acute renal failure, the scope of its use is sharply limited by a one-off procedure to relieve the acute phase of hypercalcemia.
As a drug for prolonged therapy of hypercalcemia, a solution of neutral phosphate should be used orally. The only contraindication for its use is a severe degree of renal failure.
In the case of hypercalcaemia in the background of hyperparathyroidism, which has a progressive course, the use of surgical methods of treatment is indicated. The detection of localization of parathyroid tissue can be a certain complication, for which various radial imaging methods are used, but the method of computed tomography has the highest reliability in this situation. The performed operation is considered successful if the serum calcium concentration is normalized within 24 hours.