Hypomagnesemia in Post Thyroidectomy Patient: An Underestimated Entity

In post thyroidectomy patients hypocalcemia is one of the known complication many factors play important role in calcium hemostasis and magnesium is one among them. So this study was conducted to assess the prevalence of hypomagnesemia in post thyroidectomy patients and its relationship with calcium homeostasis.

A prospective observational study was conducted among 31 patients who underwent total thyroidectomy or completion thyroidectomy over a period of 1 year. Patient's pre-operative and post-operative day 1 and day 2 serum calcium, magnesium and iPTH was recorded and their correlation was analyzed using SPSS 21.0. and p value of < 0.05 was taken as statistically significant. Calcium supplementation was only given to patients who developed symptomatic hypocalcemia in postoperative period.

In our study hypomagnesemia in post thyroidectomy patients on post -operative day 1 and day 2 was 71% and 74.2% respectively. Hypocalcemia was seen in 64.5% of patients on post-operative day 1 and 96.8% on post-operative day 2. Symptomatic hypocalcemia was seen in 22.6% of study population on post-operative day 1 and 22.6% of patients on post-operative day 2 while 25.8% patients newly developed symptoms of hypocalcemia. Statistically significant correlation was found between calcium and magnesium levels in post op day 1(< 0.001) and post op day 2(< 0.004) and also statistically significant correlation was found between post-operative day 1 magnesium levels and post-operative day 2 calcium levels (0.001). Symptomatic hypocalcemia was more commonly seen among patients who had hypomagnesemia along with hypocalcemia though it failed to show any statistical significance.

Post thyroidectomy hypomagnesemia is frequent event and magnesium acts as an independent risk factor in development of post thyroidectomy hypocalcemia. Hypomagnesemia tends to alleviate symptomatic hypocalcemia in post thyroidectomy patients. So the role of magnesium correction to alleviate severe hypocalcemia needs to be further studied.