The role of magnesium in the correction of postoperative hypocalcemia

Abstract

Background. The postoperative hypoparathyroidism remains a specific complication in the thyroid surgery. The incidence of iatrogenic hypoparathyroidism ranges from 3.0 % to 31.5 %. The decrease in the level of parathyroid hormone leads to the launch of a cascade of the electrolyte changes. The standard methods for controlling and correcting hypoparathyroidism do not guarantee the prevention of hypocalcemiacases. The role of calcium and magnesium in the conduction of the nerve impulses along muscle fibers is well known. The study of the role of magnesium will enable further correction of the manifestations of postoperative hypoparathyroidism.Aim — to study a relationship between postoperative hypoparathyroidism, changes in calcium-magnesium metabolism and their clinical manifestations; to analyze the effects of hypomagnesemia on the clinical manifestations of hypocalcemia; to study the possibility of correcting calcium-magnesium metabolism in the postoperative period.Materials and methods. The study involved 145 patients operated for the thyroid diseases. The patients were divided into two groups. The main group (n = 73) included the patients who took magnesium medications in the preoperative period for 10—14 days at a dose of 1500—2000 mg/day. In the observation group (n = 72), the patients did not take the magnesium medications. Parameters of the parathyroid hormone, ionized calcium, and magnesium were measured in all patients in the preoperative period and on the first day of the postoperative period. The parathyroid hormones’levels on the first day of postoperative period were ranged into the “ranges”: 1) parathyroid hormone — ≤ 1 pg/ml, 2) parathyroid hormone — 1—5 pg/ml, 3) parathyroid hormone — 5—10 pg/ml, 4) parathyroid hormone — > 10 pg/ml. The clinical manifestations of hypoparathyroidism were assessed on a scale: not pronounced, poorly pronounced, pronounced, sharply pronounced.Results. The correlations were found between the levels of the postoperative magnesium, ionized calcium and parathyroid hormone. In the main group, the number of the pronounced and sharply pronounced manifestations of hypocalcemia was observed in the parathyroid hormone range — ≤ 1 pg/ml. In the observation group, the largest number of the prono­unced and sharply pronounced clinical manifestations was recorded in the parathyroid hormone range — ≤ 1 pg/ml, parathyroid hormone — 1—5 pg/ml. In the main group, in comparison with the observation group, the total number of the clinical manifestations of hypocalcemia was lower.Conclusions. There were revealed the positive cor­rela­tions in the changes in the levels of the parathyroid hormone, ionized calcium and magnesium. It has been proven that uncorrected hypomagnesemia in the early postoperative period can be a predictor of the clinical manifestations of hypoparathyroidism. The correction of the serum magnesium levels in most patients reduces the clinical manifestations of hypocalcemia.