Prediction of the parathyroid gland function and prognosis after thyroid surgery by monitoring drainage fluid and serum parathyroid hormone and serum calcium

Abstract

Objective To explore the dynamic variation rule of drainage fluid parathyroid hormone （ dPTH） , serum parathyroid hormone （ PTH） and serum calcium after thyroidectomy .According to the variation rule, the survival , function and prognosis of the parathyroid which retained at the original place can be predicted . Methods From Apr.2012 to Aug.2012, 90 patients who underwent thyroidectomy in Thyroid Surgery Center of the First Affiliated Hospital of Kunming Medical University were chosen as the research object .All of the objects’operations were performed by the same surgeon team and they were divided into four groups according to different surgical methods （ group A：bilateral thyroidectomy group , group B：bilateral thyroidectomy and central neck dis-section group , group C： bilateral thyroidectomy and functional neck dissection group , and group D： unilateral thyroidectomy group ） .Parathyroid retention situation during operation and the occurrence of hypocalcaemia after operation were recorded .Blood samples were taken between 7am and 8am in the 4 consecutive days after opera-tion to detect serum calcium and serum parathyroid hormone .All of the 90 patients had the drainage tube and their drainage fluid were taken for testing dPTH .The levels of serum calcium , PTH and dPTH were analyzed by＆amp;nbsp;statistical analysis of repetitive measure analysis of variance （ ANOVA） .Results The mean postoperative maxi-mum serum calcium was in group D and the minimum was in group C .There was no obvious difference in terms of serum calcium between group A and group B .However , the serum calcium showed an upward trend in each group.The mean postoperative maximum PTH was in group D and the difference has statistical significance com -pared to the other 3 surgical methods.The minimum was in group B and group C .However, it showed an upward trend with time in each group .The difference of dPTH in each group had no statistical significance and it showed a downward trend in all the 4 groups.Low serum calcium and hypocalcaemia occurred to 22 cases and 13 cases respectively after operation .The low serum calcium cases in each group were 12, 3, 4 and 2 respectively and hy-pocalcaemia cases in each group were 4, 3, 1 and 1 respectively.Conclusions By monitoring dPTH, PTH and serum calcium after thyroidectomy , the survival and function of parathyroid retained at the original place can be e-valuated comprehensively .Furthermore, it also helps to estimate prognosis .dPTH at a high level after operation is a direct evidence that parathyroid retained at the original place survives .Low PTH and high dPTH after thyroid-ectomy illustrates the operation just affects the way that PTH secreted into blood and the parathyroid retained at the original place can still secrete large amount of PTH .PTH will return to normal gradually with reconstruction and healing of microcirculation around parathyroid .Persistent low serum PTH after operation , low dPTH after 24 hours and the early advent of hypocalcaemia suggest the parathyroid retained at the original place was injured seri -ously and its blood supply was damaged obviously and more than one parathyroid were affected .Secretion function of parathyroid will remarkably decrease . Key words: Thyroidectomy; Drainage fluid parathyroid hormone; Serum parathyroid hormone; Parathyroid