Analysis Of Changes Of Hypoparathyroidism And Strategy Of Preventive Calcium Supplementation After Thyroidectomy

[Objective]To investigate the changes of serum parathyroid hormone(PTH),serum calcium(Ca)and serum phosphate(P)levels after thyroidectomy,explore the relationship between post-thyroidectomy hypocalcaemia and hypoparathyroidism,as well as the influencing factors for post-thyroidectomy hypoparathyroidism,analyze the rule of changes of serum parathyroid hormone,serum calcium and serum phosphate levels,and explore the strategy of preventive calcium supplementation.[Methods]From Oct.2016 to Nov.2016,93 patients accepted thyroidectomy in Department of otolaryngology,Qilu Hospital of Shandong University(Qingdao).Serum parathyroid hormone,serum calcium and serum phosphate levels were examined preoperatively and at 30min,ld,2d,3d,7d and 30d postoperatively.According to the serum concentration of PTH at 30min postoperatively,patients were classified into group A(PTH?15pg/ml and PTH changed?20%),B(PTH>15pg/ml and PTH decreased>20%),C(8pg/ml?PTH<15pg/ml)and D(PTH<8pg/ml),and they were compared in terms of postoperative changes of PTH and serum calcium.Statistical analysis was performed.[Results](1)Of the 93 patients,the incidence of hypoparathyroidism was 14%(13 patients),and hypocalcaemia 11.8%(11 patients)including 3 patients had symptoms,all the patients had no permanent hypoparathyroidism;(2)The lower the serum concentration of PTH is,the higher the rate of hypocalcemia and symptomatic hypocalcaemia occurs;(3) Univariate analysis showed pathological type(P=0.031),whether total thyroidectomy(P<0.001),central neck dissection(P=0.002),lateral neck dissection(P=0.012)were related to hypoparathyroidism;(4)Mutivariateanalysis showed whether total thyroidectomy(P=0.047)was related to hypoparathyroidism independently;(5)The serum concentration of PTH,serum calcium and serum phosphate changed significantly after different kinds of surgery,the bigger of the extent of operation,the higher of the rate of hypoparathyroidism(P<0.01);(6)The lower the serum PTH examined at 30min postoperatively is,the slower the serum concentration of PTH recover.When serum concentration of PTH examined at 30min postoperatively lower than 8pg/ml,the serum concentration of PTH examined at 7d postoperatively lower than normal;(7)The serum Ca was lower and serum P is higher than normal when hypoparathyroidism,the extent related to the serum concentration of PTH examined at 30min postoperatively,when PTH examined at 30min postoperatively lower than 8pg/ml,the serum Ca and serum P changed greatly and recover slowly.[Conclusion](1)Hypocalcemia is associated with the reduction of parathyroid hormone;The pathological type and extent of surgery were more likely to result hypoparathyroidism,total thyroidectomy was related to hypoparathyroidism independently.(2)the serum concentration of PTH examined at 30min postoperatively can reflect the recovery of the function of parathyroid glands and whether symptomatic hypocalcaemia or not.For patients accepted total thyroidectomy,the level of the serum concentration of PTH examined at 30min postoperatively is beneficial for making strategy of preservation of hypocalcaemia.