A large, new study confirms risk factors for severe hypocalcemia after total parathyroidectomy (PTx) without autotransplantation in patients with secondary hyperparathyroidism (SHPT).
Severe hypocalcemia, defined as postoperative serum calcium levels less than 1.78 mmol/L, developed in 25.9% of 1095 patients with SHPT treated with total PTx from 2008 to 2018 The most common clinical symptoms were bone pain (87.3% vs 77.1%) and pruritus (45.8% vs 57%).
After binary logistic regression analyses, low serum calcium (median 2.4 vs 2.5 mmol/L), high intact parathyroid hormone (iPTH; median 2304.9 vs 1239.7 pg/mL), and high alkaline phosphatase (ALP; median 528.2 vs 159.5 U/L) levels prior to PTx emerged as independent predictors of severe hypocalcemia – in line with previous research, Junwei Yang, MD, of the Second Affiliated Hospital of Nanjing Medical University in China, and colleagues reported in the International Journal of Endocrinology. High preoperative iPTH and ALP were significantly associated with 46- and 10-fold increased odds of severe hypocalcemia. High preoperative calcium was significantly associated with 95.8% decreased odds. The investigators explained that an elevated serum ALP level indicates an increase in bone metabolism and is associated with osteoporosis.
None of the other factors evaluated, including sex, hemodialysis vintage, duration of kidney failure, underlying kidney diseases, serum phosphorus levels, serum albumin levels, and vascular calcification, were predictive.
“Patients with high preoperative ALP levels should undergo close monitoring of the serum calcium level in the early postoperative period, particularly those in the high dependency unit, to avoid the complication of early postoperative [severe hypocalcemia],” Dr Yang’s team stated. “Postoperative empirical intravenous calcium supplementation should be administered in the immediate postoperative period and at a higher dose in high-risk patients.”
Wen P, Xu L, Zhao S, et al. Risk Factors for severe hypocalcemia in patients with secondary hyperparathyroidism after total parathyroidectomy. Int J Endocrinol. Published online April 2, 2021. doi:10.1155/2021/6613659