title: Early prediction of oral calcium and vitamin D requirements in post-thyroidectomy hypocalcaemia.
abstract: OBJECTIVE
  To optimize and individualize post-thyroidectomy hypocalcemia management.
  
  
  METHODS
  A multicenter prospective cohort study.
  
  
  METHODS
  Two tertiary care hospitals.
  
  
  METHODS
  parathyroid hormone (PTH) was measured preoperatively, then at 1 and 6 hours after surgery. The required doses of calcium and vitamin D were defined as those maintaining the patients asymptomatic and their cCa ≥ 2 mmol/L. They were used as an endpoint in a generalized linear mixed effect model (GLIMMEX) aiming to identify the best predictors of these optimal required doses. Models were evaluated by goodness of fit and Receiver Operating Characteristic (ROC) curves.
  
  
  RESULTS
  One hundred and sixty-eight patients were analyzed; 85.1% were female, 49.3% had BMI > 30, and 64% had vitamin D deficiency. Post-thyroidectomy hypocalcemia was found in 25.6%, of whom 18 (41.9%) were symptomatic and received intravenous calcium. First hour percentage of drop in PTH correlated positively with the severity of hypocalcemia (P < .0001). The GLIMMIX prediction model for oral calcium requirement was based on first-hour percentage change from preoperative PTH level, preoperative actual PTH, BMI, and thyroid function. The same predictors were identified for vitamin D, except that thyroid function was replaced with vitamin D status. These factors were used to build predictive equations for calcium and vitamin D doses.
  
  
  CONCLUSIONS
  Our findings help to optimize management of post-thyroidectomy hypocalcemia by assisting in the early identification of those who are not at risk of hypocalcaemia and by guiding early effective management of those at risk. This may reduce complications and medical cost.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, King Fahad Medical City, Riyadh, Saudi Arabia Department of Otolaryngology, Head and Neck Surgery, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Saleh F
authors.initials: SF
authors.lastname: Al-Dhahri
authors.affiliation: Department of Biostatistics, Research Center, King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Mubasher
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Fida
authors.initials: F
authors.lastname: Al-Muhawas
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Alessa
authors.affiliation: King Fahad Medical City, Riyadh, Saudi Arabia.
authors.forename: Rayan S
authors.initials: RS
authors.lastname: Terkawi
authors.affiliation: Department of Anesthesiology, King Fahad Medical City, Riyadh, Saudi Arabia Department of Anesthesiology, University of Virginia, Charlottesville, Virginia, USA asterkawi@gmail.com.
authors.forename: Abdullah S
authors.initials: AS
authors.lastname: Terkawi
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D015992:Body Mass Index; D002118:Calcium / Q000008:administration & dosage*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006996:Hypocalcemia / Q000188:drug therapy* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D011183:Postoperative Complications / Q000097:blood / Q000188:drug therapy; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies; D013960:Thyroid Function Tests; D013965:Thyroidectomy / Q000009:adverse effects* / Q000379:methods; D016896:Treatment Outcome; D014807:Vitamin D / Q000008:administration & dosage*; D014808:Vitamin D Deficiency / Q000188:drug therapy / Q000209:etiology
chemical_list: D010281:Parathyroid Hormone; D014807:Vitamin D; D002118:Calcium
keywords: BMI; PTH; calcium; post-thyroidectomy hypocalcemia management; vitamin D