Clin Exp Otorhinolaryngol.  2011 Jun;4(2):95-100.

Reliable Early Prediction for Different Types of Post-Thyroidectomy Hypocalcemia

• Kim JH
• Chung MK
• Son YI

Abstract

OBJECTIVES
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.
CONCLUSION
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.

Keyword

Hypocalcemia; Parathyroid hormone; Thyroidectomy; Early diagnosis; Postoperative complicationns

MeSH Terms

Calcium
Early Diagnosis
Hospitalization
Humans
Hypocalcemia
Incidence
Parathyroid Hormone
Retrospective Studies
Thyroidectomy
Biomarkers
Calcium
Parathyroid Hormone

Figure

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  Fig. 1 Mismatch on the occurrence of symptomatic and biochemical hypocalcemia. In 45 patients of the S+B+ group (triangles), 24 patients presented with symptomatic and biochemical abnormalities on the same day (triangles along a dotted line) and the remaining 21 patients on different days of the hospital stay (scattered triangles). Nine patients presented with only symptomatic hypocalcemia (S+B- group, rectangles), while 8 patients revealed only biochemical hypocalcemia (S-B+ group, circles).

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