Analysis of risk factors of severe hypocalcemia after total parathyroidectomy

Abstract

Objective To analyze the incidence and risk factors of hypocalcemia after total parathyroidectomy without autotransplantation. Methods A total of 783 maintenance hemodialysis patients who underwent TPTX in the Second Affiliated Hospital of Nanjing Medical University from September 2008 to September 2017 were included in the study. The preoperative blood biochemical examination, preoperative iPTH, total mass of parathyroid gland (M) and postoperative iPTH and electrolyte results were collected. The incidence of severe hypocalcemia after TPTX were analyzed retrospectively. Binary logistic regression model was used to analyze the risk factors of severe hypocalcemia after TPTX. Results The age of 783 patients with TPTX was (46.90±10.78) years old, and the average dialysis age was (91.36±41.75) months. Postoperative severe hypocalcemia occurred in 235 cases (30.01%). Binary logistic regression analysis showed that higher preoperative blood iPTH (OR=7.56, 95% CI: 1.55-36.79, P=0.01), higher blood alkaline phosphatase (OR=36.71, 95% CI: 14.75-91.36, P<0.01), blood phosphorus (OR=1.74, 95%CI: 1.11-2.71, P=0.02) and greater mass of resected glands (OR=1.18, 95% CI: 1.06-1.31, P<0.01) were the risk factors for post-hypocalcemia. The higher preoperative serum calcium can reduce the risk of postoperative hypocalcemia (OR=0.02,95% CI: 0.01-0.07, P<0.01). Conclusions The incidence of hypocalcemia after TPTX treatment for SHPT is very high. Blood iPTH, alkaline phosphatase, phosphorus, and total mass of intraoperative parathyroid gland excision are the independent risk factors for severe hypocalcemia after surgery. Key words: Secondary hyperparathyroidism; Parathyroidectomy; Hypocalcemia