title: Reliable early prediction for different types of post-thyroidectomy hypocalcemia.
abstract: OBJECTIVE
  High incidence of hypocalcemia after thyroidectomy is a major determinant in delay of discharge. Even though many studies have focused on the search for reliable early predictors of postoperative hypocalcemia, definitions of hypocalcemia are diverse; therefore, interpretation and application of previously reported findings may not be easy. We aimed to elucidate diverse patterns of post-thyroidectomy hypocalcemia and to provide reliable early predictors for these different types of hypocalcemia.
  
  
  METHODS
  Retrospective chart review was performed and eligible 112 patients of thyroidectomy were categorized into four groups according to symptomatic and/or biochemical hypocalcemic criteria. A mismatch of occurrence and the timing of symptomatic or biochemical abnormalities were evaluated. Predictive values of commonly used biomarkers were compared in each group; levels of serum total calcium and ionized calcium, and intact parathyroid hormone (PTH).
  
  
  RESULTS
  Among 62 hypocalcemic patients, 45 patients (72.5%) experienced both symptomatic and biochemical abnormalities during hospitalization. A mismatch on the timing of initial detection of symptomatic and biochemical hypocalcemia was observed in 21 patients (46.6%). Intact PTH level measured at 1 hour was a useful indicator in prediction of symptomatic hypocalcemia with 79.7-87.4% of diagnostic accuracy. Serum ionized calcium measured next morning after surgery was a reliable predictor of biochemical hypocalcemia with 77.9-94.8% of diagnostic accuracy.
  
  
  CONCLUSIONS
  For the safety of patients, the possibility of both symptomatic and biochemical hypocalcemia should be considered together before deciding early discharge. Using intact PTH for symptomatic hypocalcemia and day-1 ionized serum calcium level for biochemical hypocalcemia will be helpful for the reliable prediction of heterogeneous nature of postoperative hypocalcemia.
authors.affiliation: Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Joon Ho
authors.initials: JH
authors.lastname: Kim
authors.forename: Man Ki
authors.initials: MK
authors.lastname: Chung
authors.forename: Young-Ik
authors.initials: YI
authors.lastname: Son