Value of the 6-hour postoperative ionized calcium slope in predicting post- thyroidectomy occurrence of hypocalcemia

ABSTRACT

@#<p style="text-align justify;"><strong>OBJECTIVE: </strong>To determine the value of the 6-hour postoperative ionized Calcium (iCa) slope, versus 6-hour postoperative Calcium alone in predicting the occurrence of hypocalcemia in patients who underwent thyroid surgery in a tertiary hospital in Metro Manila.<br /><br /><strong>METHODS:</strong><br /><strong>Design: </strong>Retrospective cross-sectional study<br /><br /><strong>Setting: </strong>Tertiary Private Hospital<br /><br /><strong>Subjects: </strong>Pre-operative and 6-hour postoperative ionized calcium determinations were analyzed in 59 patients of the ENT-HNS Department in a tertiary hospital in Metro Manila who underwent thyroid surgery from January 2009 to December 2013.<br /><br /><strong>RESULTS:</strong> The 6-hour postoperative iCa slope (difference between the pre-operative and 6-hour postoperative iCa levels) of ?0.18 mmol/L correctly predicted 57.1% of patients who eventually developed hypocalcemia, with a specificity of 81.6% and a positive predictive value of 63.2%. In contrast, the 6-hour postoperative iCa measurement identified only 23.8% (5 out of 21) patients who developed hypocalcemia.<br /><br /><strong>CONCLUSION:</strong> The 6-hr postoperative iCa slope increased the probability of identifying patients who developed hypocalcemia from 23.8% to 57.1%. However, as a single determination, this may  not suffice to take the place of serial iCa measurements after thyroid surgery.</p>