title: Parathyroid hormone levels 1 hour after thyroidectomy: an early predictor of postoperative hypocalcemia.
abstract: BACKGROUND
  Parathyroid dysfunction leading to symptomatic hypocalcemia is not uncommon following a total or completion thyroidectomy and is often associated with significant patient morbidity and a prolonged hospital stay. A simple, reliable indicator to identify patients at risk would permit earlier pharmacologic prophylaxis to avoid these adverse outcomes. We examined the role of intact parathormone (PTH) levels 1 hour after surgery as a predictor of post-thyroidectomy hypocalcemia.
  
  
  METHODS
  We prospectively reviewed the cases of consecutive patients undergoing total or completion thyroidectomy. Ionized calcium (Ca(2+)) and intact PTH levels were measured preoperatively and at 1-, 6- and 24-hour intervals postoperatively. The specificity, sensitivity, negative and positive predictive values of the 1-hour PTH serum levels (PTH-1) in predicting 24-hour post-thyroidectomy hypocalcemia and eucalcemia were determined.
  
  
  RESULTS
  We reviewed the cases of 149 patients. Biochemical hypocalcaemia (Ca(2+) < 1.1 mmol/L) developed in 38 of 149 (25.7%) patients 24 hours after thyroidectomy. The sensitivity, specificity, positive and negative predictive values of a low PTH-1 were 89%, 100%, 97% and 100%, respectively.
  
  
  CONCLUSIONS
  We found that PTH-1 levels were predictive of symptomatic hypocalcemia 24 hours after thyroidectomy. Routine use of this assay should be considered, as it could prompt the early administration of calcitriol in patients at risk of hypocalcemia and allow for the safe and timely discharge of patients expected to remain eucalcemic.
authors: The Division of Surgical Oncology, McGill University, Montréal, Que., and the Division of General Surgery, King Saud University, Riyadh, Saudi Arabia.
authors: Awad
authors: A
authors: AlQahtani
authors: The Division of General Surgery, McGill University, Montréal, Que.
authors: Armen
authors: A
authors: Parsyan
authors: The Department of Otolaryngology, McGill University, Montréal, Que.
authors: Richard
authors: R
authors: Payne
authors: The Division of Surgical Oncology, and the Division of General Surgery, McGill University, Montréal, Que.
authors: Roger
authors: R
authors: Tabah
mesh_terms: D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood*; D011183:Postoperative Complications / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D011184:Postoperative Period; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013965:Thyroidectomy
chemical_list: D015415:Biomarkers; D010281:Parathyroid Hormone