Postoperative HypocalcemiaMedical editor Lars H. Jørgensen MD
Oslo University Hospital
After a total thyroidectomy, it is not uncommon to have symptoms of hypocalcemia for a short period. Acute hypocalcemia occurs most often during the first postoperative days.
In some cases, the condition is permanent. If hypocalcemia continues for more than one year, the patient has permanent postoperative hypocalcemia.
The incidence of permanent postoperative hypocalcemia is about 0.5 - > 2% depending on the experience of the surgeon and the extent of the local disease. With a reoperation, the risk for postoperative hypocalcemia is significantly greater, which is why it is very important that the first surgery is radical.
- Postoperative hypocalcemia
Causes may be:
- Operation trauma with edema following the surgery.
- The vessel supply to the parathyroid gland may be damaged or temporarily reduced.
- The parathyroid glands were difficult to identify and were included in the resected specimen.
Acute postoperative hypocalcemia is often a scary and traumatic experience for the patient. It is therefore important that the patient is informed before the operation.
- tingling and numbness in the extremities and face
- seizures can occur from severe hypocalcemia
Oral calcium supplementation is recommended. If calcium treatment is started early, intravenous treatment can usually be avoided.
Treatment is calcium tablets/fizz tablets 500 mg x 1-8 (sometimes more) daily. The risk of overdose with calcium tablets is very small.
With serious hypocalcemia, a slow calcium infusion should be given intravenously. Some may require a calcium infusion for multiple days.
Calcium tablets 500 mg 1-2 as needed, possibly 6-8 (10) tablets daily to treat symptoms. The patient should be followed-up closely until stable.
If the symptoms last for more than 4 weeks, treat with a vitamin D analog and 500 mg calcium or more, if needed.
Calcium with D vitamin should be discontinued gradually. It is important not to overtreat. Ca2+ should be in the lower normal range, since it will stimulate the remaining parathyroid tissue.
Check ionized calcium with two week intervals until a stable level is reached. Ionized calcium should be maintained in the lower normal limit to maintain the endogenous stimulation of the parathyroid gland.
PTH should be measured every two months for parathyroid function. If PTH is measureable in the normal area and all symptoms of hypcalcemia disappear, treatment should be stopped, since the parathyroid glands may have been restored.
If the patient has permanent hypocalcemia, they will need life-long treatment with vitamin D and regular follow-up of calcium status.
Calcium (ionized or albumin) should be checked every 3-6 months when levels have stabilized.
Calcium and phosphate secretion in urine should be monitored. Vitamin D treatment poses a risk for high calcium secretion from the kidneys, which increases the risk for developing kidney disease, especially if the s-calcium and s-phosphate values are high. The vitamin D dose should be kept low, avoid high phosphate values, and reduce renal secretion by supplementing with magnesium, thiasid, or a phosphate binder.