Prevention of post-thyroidectomy hypocalcemia
by calcium and vitamin D therapy
(March 2003)
The background of the study. Serum
calcium concentrations can fall enough to cause symptoms (numbness
and tingling of the hands, feet, and around the mouth; and muscle
cramps) one or two days after thyroid surgery because of injury
to the parathyroid glands. In this study the efficacy of routine
calcium and vitamin D treatment for preventing hypocalcemia after
total thyroidectomy was studied.
How the study was done. Seventy-nine
patients were randomly assigned to receive calcium, calcium and
calcitriol (a form of vitamin D), or neither, starting one day after
total thyroidectomy. Treatment consisted of 1000 mg of elemental
calcium three times daily, the same dose of calcium and 0.5 µg
of calcitriol twice daily, or neither. The patients were examined
and serum calcium was measured 1, 2, 3 (the day of discharge), and
7 days after surgery. Low serum calcium (hypocalcemia) was defined
as a serum calcium value <8.0 mg/dl, even if it was present on
only one occasion. Treatment was reduced starting on day 3 and stopped
in most patients on day 7.
The results of the study. Among
the 27 patients in the no-therapy group, 11 (41 percent) had symptoms
of hypocalcemia, and were treated with calcium and calcitriol. In
contrast, only 5 (10 percent) of the 52 patients in the other groups
had hypocalcemia (and only two were given calcitriol). The average
serum calcium concentrations were similar in the three groups (the
values include the values for the patients who were being treated).
The calcium and calcitriol treatment was stopped by day 7 in all
but 8 patients and within the next 21 days in 6 of them.
The conclusions of the study. Treatment
with calcium alone or calcium and calcitriol for 7 days after thyroidectomy
prevents hypocalcemia.
The original article. Bellantone
R, Lombardi CP, Raffaelli M, Boscherini M, Alesina PF, De Crea C,
Traini E, Princi P. Is routine supplementation therapy (calcium
and vitamin D) useful after total thyroidectomy? Surgery 2002;132:1109-13.
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