title: Impact of postoperative magnesium levels on early hypocalcemia and permanent hypoparathyroidism after thyroidectomy.
abstract: BACKGROUND
  Postoperative hypocalcemia is a common complication of thyroidectomy. Magnesium is known to modulate serum calcium levels and hypomagnesemia may impede correction of hypocalcemia. The purpose of this study was to investigate whether hypomagnesemia after thyroidectomy has any impact on early hypocalcemia and/or permanent hypoparathyroidism.
  
  
  METHODS
  We conducted a retrospective review of prospectively maintained databases. Inclusion criteria were total or completion total thyroidectomy with postoperative magnesium levels available. The incidence of postoperative hypocalcemia was correlated with postoperative hypomagnesemia and other risk factors.
  
  
  RESULTS
  Two hundred one cases were included. Twenty-six patients (13%) developed postoperative hypomagnesemia. Hypomagnesemia (p = .002), cancer diagnosis (p = .01), central neck dissection (p = .02), and inadvertent parathyroid resection (p = .02) were significantly associated with hypocalcemia. On multivariate analysis, only hypomagnesemia (p = .005) remained significant. Hypomagnesemia was also a significant predictor of permanent hypoparathyroidism (p = .0004).
  
  
  CONCLUSIONS
  Hypomagnesemia is significantly associated with early hypocalcemia and permanent hypoparathyroidism after thyroidectomy. Magnesium levels should be closely monitored in patients with postthyroidectomy hypocalcemia.
authors.affiliation: Department of Endocrinology, South Infirmary Victoria University Hospital, Cork, Ireland.
authors.forename: Aoife
authors.initials: A
authors.lastname: Garrahy
authors.affiliation: Department of Endocrinology, South Infirmary Victoria University Hospital, Cork, Ireland.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Murphy
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, South Infirmary Victoria University Hospital, Cork, Ireland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Sheahan
mesh_terms: D002118:Calcium / Q000097:blood; D005260:Female; D006801:Humans; D006996:Hypocalcemia / Q000097:blood* / Q000209:etiology; D007011:Hypoparathyroidism / Q000097:blood* / Q000209:etiology; D015994:Incidence; D008274:Magnesium / Q000097:blood*; D008297:Male; D011183:Postoperative Complications; D011184:Postoperative Period; D012189:Retrospective Studies; D012307:Risk Factors; D013965:Thyroidectomy / Q000009:adverse effects*
chemical_list: D008274:Magnesium; D002118:Calcium
keywords: hypocalcemia; hypoparathyroidism; magnesium; parathyroid; thyroidectomy