Predicting Hypocalcemia Post-Thyroidectomy with Intraoperatory PTH in Children: Validation of a Proposed Algorithm and Improvement in Hospitalization Days

PAPENDIECK, PATRICIA ; RODRIGUEZ, MARIA EUGENIA; ROPELATO, MARÍA GABRIELA; RODRIGUEZ AZRAK, SOL; ELÌAS, EUGENIA; BERGADÁ, IGNACIO; FREIRE, ANALIA; VIEITES, ANA ; BALLERINI, MARÍA GABRIELA; CHIESA, ANA

Buenos Aires

Congreso; XXVI Reunion Anual de la Sociedad Latinoamericana de Endocrinología Pediatrica; 2016

Background: In a previous report we proposed and algorithmwith intraoperatory PTH at 5 and 60 minutes post thyroidectomy(TX) (PTH-5) (PTH-60) for predicting hypocalcemia (Freire et al,Surgery 2015)*.Objetives:To validate our cut-off values as predictors of hypocalcemia.To evaluate the impact of the propose strategy on:? Reduction on the occurrence of clinical and/or biochemicalhypocalcaemia.? Reduction on the period of hospitalization post TX and serumcalcemic controls (sCa+).Methods: Patients were prospectively classified according totheir risk of hypocalcaemia in:G1: High risk: PTH-5: ≤16 pg/mL or PTH-5 16?20 pg/ml withPTH-60: ≤16 pg/mL; IV Calcium was infused immediately afterTX, 1-25OHVit D and oral Calcium were introduced within 24?48hs after TX according to oral tolerance.G2: Low risk: PTH-5: >20 pg/mL or PTH-5 16?20 pg/mL withPTH-60: >16 pg/mL, underwent clinical controls of hypocalcemiaevery 6 h and sCa+ performed when present; sCa+ was checked at24 and 48 h after TX, if normal, patient was discharged.Presence of signs/symptoms of hypocalcaemia, days of hospitalizationand number of sCa+ in low risk patients were recordedand compared with those of our historical thyroidectomized group(HG) (32 patients, 15 with hipocalcemia)*.(PTH assay: ECLIA,COBAS e-411, Roche Diagnostics).Results: 21 children, aged (median, range) 12.7 (3.8?19) years,18 girls) were included. Seven fell in G1 and 14 in G2. Five patientsfrom G1 remained asymptomatic and had transient hypoparathyroidism.The remaining 2 developed mild hypocalcemic symptomswith definitive hypoparathyroidism. None of G2 patients developedhypocalcaemia due to hypoparathyroidism, 1 hyperthyroidgirl had mild hypocalcemia related to hungry bone syndrome.Hospitalization lasted 3 (4?6) days in G1, vs. 6 (3?18) days in HG(p < 0.01). G2 remained hospitalized 2 (1?3) days and their sCa+controls were 2 (1?4) vs. 5 (4?6) in HG (p < 0.001).Conclusions: This study has validated our proposed algorithmto identify patients at risk of hypocalcaemia post TX and allowedavoiding hypocalcaemia, decreasing days of hospitalization andcalcemic controls post-TX. Therefore, this strategy consequentlyreduced health costs related to the surgical procedure.