[Diagnostic value of intraoperative parathyroid hormone decline in prediction of hypocalcemia after total thyroidectomy].
OBJECTIVE
Transient or definitive hypocalcemia is one of the most important complications following total thyroidectomy. Monitoring of serum calcium levels or calcium replacement in all patients are methods commonly used to avoid this problem. Our objective was to validate the intraoperative parathormone assay (PTH) as a predictive tool in these situations.


METHODS
We conducted a prospective study of 46 patients undergoing total thyroidectomy. PTH levels were obtained during the anesthetic induction, 10min after the procedure and 24h after surgery. Calcium levels were obtained 24 and 48h after surgery. The predictive value of postoperatory levels of PTH and its decline respect the preoperatory levels for prediction of hypocalcemia was measured. Hypocalcemia was defined as an ionized calcium<4mg/dl (<1mmol/l).


RESULTS
Of 46 patients, 13 (28.3%) developed hypocalcemia. Isolated postoperative PTH level was a poor predictor of hypocalcemia. Nevertheless, when the gradient between preoperative and postoperative levels of PTH was considered, the rate of the decline became a good predictor of hypocalcemia, with 85-90% being the most accurate cut-off point.


CONCLUSIONS
The decline of PTH in the immediate postoperative period of patients undergoing total thyroidectomy is a reliable test for predicting hypocalcemia.
Flores-Pastor
Benito
B
Unidad de Cirugía Endocrina, Servicio de Cirugía General, Hospital Universitario J.M. Morales Meseguer, Murcia, España. benitom.flores@carm.es
Miquel-Perelló
Joana
J
Del Pozo
Pablo
P
Pérez
Alfonso
A
Soria-Aledo
Víctor
V
Aguayo-Albasini
José Luis
JL
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000097:blood* / Q000209:etiology*; D007430:Intraoperative Care; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013965:Thyroidectomy / Q000009:adverse effects*
D010281:Parathyroid Hormone