Hypocalcemia after thyroidectomy: iPTH levels and iPTH decline are predictive? Retrospective cohort study

Abstract

BackgroundHypocalcemia is the most common complication of thyroid surgery. The aim of this study was to determine the early predictive factors of postoperative hypocalcemia and to analyze their efficiency.MethodsWe performed a retrospective study of 345 consecutive patients who underwent total thyroidectomy at the Endocrine Surgery Department (Policlinico G. Rodolico Hospital of Catania) between January 2011 and November 2013. We measured serum intact parathormone (iPTH) levels preoperatively and 4 h after surgery. The threshold values of hypocalcemia for iPTH levels and iPTH relative decline were obtained by receiver operating curves (ROC) analysis.ResultsThe incidence of hypocalcemia was 32.2% (111 of 345 patients). Our statistical analysis revealed that hypocalcemia rate was strongly correlated with the lower iPTH values and greater iPTH decline (P < 0.001). The threshold enabling prediction of hypocalcemia were 12,5 pg/mL for iPTH and 55,7% for relative iPTH decline. Patients with iPTH <12,5 pg/mL developed hypocalcemia in 58.6% of cases while those with iPTH ≥12,5 pg/dl in 18.8%. Among 175 patients with iPTH relative decline greater than 55,7% hypocalcemia was diagnosed in 91 cases (52%), while other 170 patients with iPTH relative decline less than 55,7% developed hypocalcemia only in 20 cases (11,7%).ConclusionsThe decreased iPTH levels and increased iPTH relative decline resulted to be an accurate predictive factors of postoperative hypocalcemia. The early administration of Calcium and vitamin D in the high-risk patients should be put on in order to prevent the symptoms of hypocalcemia and to reduce the costs and duration of hospitalization.

Randomized Controlled Trial Comparing White Light with Near-Infrared Autofluorescence for Parathyroid Gland Identification During Total Thyroidectomy

“…A baseline estimated incidence of 40% was used, drawing from 4 recently published international studies. 2,[4][5][6] To detect a 50% relative reduction in hypocalcemia, from 40% down to an incidence of 20%, with 95% confidence (a ¼ 0.05) and 90% power (b ¼ 0.90), 79 subjects were necessary in each group. This number was rounded up to 85 per group to account for potential subject loss.…”

“…1 The incidence of this complication reported in the literature is between 18% and 59%. [2][3][4][5][6] The most common reason for hypocalcemia is inadvertent damage to parathyroid gland circulation, which, in turn, is secondary to the glands' small size, soft texture, and variable location and number. This damage typically occurs during dissection of the thyroid capsule.…”

Tiempo óptimo para medición de paratohormona como predictor de hipocalcemia en pacientes posterior a tiroidectomía total

“…La población estudiada fue predominantemente de sexo femenino, siendo la relación hombre-mujer 1:10, superior a la reportada para Colombia de 1:8 33 y ligeramente superior a la descrita por otros autores 2,13,[28][29][30] .…”

“…La principal indicación de tiroidectomía fue la patología maligna, siendo el carcinoma papilar la histología más frecuente, lo que coincide con los reportes de AlQahtani 27 , Cayo 22 y Landry 21 , pero diferente de la mayoría de publicaciones, donde la principal causa fueron las patologías benignas 7,[11][12][13]16,18,19,25,[28][29][30]32 . El porcentaje de pacientes con hipocalcemia a las 12 horas fue cercano al 25 %, lo que se encuentra dentro del rango reportado en diversos estudios 4,7,[11][12][13]19,20,[22][23][24][25][26][27]29,31,32,34 .…”

“…La hormona paratiroidea (PTH), o paratohormona, es regulada de forma primaria por los nive-les séricos de calcio ionizado y, una vez secretada, se elimina rápidamente del plasma, con una vida media de dos a cuatro minutos 14,15 . Basados en lo anterior, múltiples estudios avalan la medición de la PTH como una prueba útil para la detección de los pacientes con alto riesgo de hipocalcemia posterior a una cirugía de tiroides; sin embargo, hay heterogeneidad sobre los métodos y la hora idónea para realizar la prueba 2,4,7,12,13,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] .…”