High urinary output as a predictor of hypoparathyroidism post total-thyroidectomy

Objective: to determine the usefulness of high urine output as a low-cost early predictor for postoperative hypoparathyroidism.. Method: A study was conducted inside The American British Cowdray Medical Center I.A.P. for a year in adult patients who underwent total thyroidectomy divided in two groups: those with post-surgical hypocalcemia and without post-surgical hypocalcemia using the 24-hour calcium levels. Urinary output of each patient was verified searching for the relation between this measurement and the probability of developing post-surgical hypoparathyroidism. Results: A total of 47 patients were studied, of whom 19 (40%) were classified with post-surgical hypocalcemia and 28 (59.5%) with no post-surgical hypocalcemia. The urinary output mean on the first 8 hours post-operatory was higher in the post-surgical hypocalcemia group in comparison with the group with no evidence of hypocalcemia, showing no significant difference (p = 0.392). Urinary output 16 hours post-surgical was no significant either (p = 0.435). Conclusions: In our study, there was no relation found between the increase of the urinary output and the post-surgical hypoparathyroidism prediction. Further studies with a bigger sample and a stronger methodologic design (prospective) are needed to determine if the difference obtained may be useful as a predictor.