Estimation of Ionized calcium levels after thyroidectomy at King Abdul Aziz University Hospital [Jeddah]

ABSTRACT

To determine the incidence of hypocalcaemia and the need for calcium supplementation after thyroid surgery in a population of 120 cases. A retrospective study was carried out on 120 patients who underwent thyroidectomy at King Abdul Aziz University hospital from January 1999 to September 2003 to determine the incidence of hypocalcaemia by measuring ionized calcium level. The data included preoperative and postoperative ionized calcium, albumin, free thyroxin, thyrotopin and alkaline phosphatase levels. The medical notes were reviewed for age, gender, type of thyroidectomy and pathological characteristics of resected thyroid tissue and autotransplantion of the parathyroid gland. Treatment of postoperative hypocalcaemia and duration of treatment was recorded. Hypocalcaemia occurred in 15% [18] patients out of a total of 120 patients who underwent total thyroidectomy. They had a significantly lower calcium level [1.78 +/- 0.054 compared to 85% [102] patients with normal calcium level]. Sixteen patients required calcium supplementation with or without oral vitamin D[3]. Three patients developed permanent hypoparathyroidism with PTH level of 23 pg/L. Two patients developed laryngeal stridor and were treated initially by intravenous infusion of calcium gluconate. It is more accurate and appropriate to measure or calculate ionized calcium level in post-thyroidectomy patients to avoid unnecessary calcium supplementation as a result of misdiagnosed hypocalcaemia due to measurement of total calcium alone