Parathyroidectomy complications: low calcium, hungry bone, voice change and neck haematoma

Why calcium falls after the operation

In primary hyperparathyroidism one or more glands overproduce parathyroid hormone while the others become suppressed. Once the abnormal tissue is removed, hormone levels drop quickly and the remaining glands need time to recover. Serum calcium often falls in the first day or two, and patients may need temporary calcium and vitamin D replacement.

Hungry bone syndrome is a more severe pattern. Bone that has been under prolonged hormone stimulation suddenly stops releasing calcium but keeps building, taking up calcium, phosphate and magnesium from the blood. Risk is greater when hyperparathyroidism was severe and long-standing with marked bone involvement. Hypocalcaemia can be profound and prolonged.

Assessment priorities in the first postoperative days

Monitor calcium at the intervals ordered and compare each result with the trend, not just the reference range. Ask specifically about tingling around the mouth and in the fingers, muscle cramps and twitching. Chvostek and Trousseau signs can support the assessment but are not reliable alone. Report worsening symptoms promptly, even before the next scheduled result. Teach the patient which symptoms to report after discharge, since calcium can continue to drift once they are home.

Severe hypocalcaemia can cause tetany, laryngospasm, seizures and a prolonged QT interval, so a patient with escalating symptoms may need cardiac monitoring and urgent intravenous calcium as prescribed. Low magnesium makes hypocalcaemia harder to correct, which is why magnesium and phosphate are often checked with calcium when hungry bone syndrome is suspected.

Voice change and recurrent laryngeal nerve injury

The recurrent laryngeal nerves run close to the thyroid and parathyroid glands and control vocal cord movement. Bruising or injury causes hoarseness and a weak voice; bruising usually recovers over weeks to months, while permanent injury is uncommon. Injury to the external laryngeal nerve can weaken the voice and limit high notes without changing its sound.

Assess voice quality after surgery and compare with the preoperative baseline, ideally documented before the operation. Ask the patient to speak a full sentence rather than answer yes or no. A mildly husky voice is common after neck surgery, but new stridor, noisy breathing or difficulty clearing secretions needs urgent review. Bilateral nerve injury is very rare but can obstruct the airway because both vocal cords may rest near the midline.

Neck haematoma is an airway emergency

Bleeding into the neck can compress the airway within a short time. Multidisciplinary guidance written for thyroid surgery, with principles that may extend to parathyroid surgery, teaches recognition through difficulty swallowing, rising early warning scores, swelling, anxiety, rapid breathing and stridor. Check the wound and neck circumference as well as the dressing, because bleeding can collect beneath an intact dressing.

If haematoma is suspected, call for urgent senior surgical and anaesthetic help, sit the patient up and give oxygen. The same guidance recommends a bedside emergency box and staff trained to open the wound when the airway is compromised, following a structured sequence. Follow your unit's protocol; delay while waiting for a scan or routine review is dangerous.

Apply the priorities to a study scenario

In a hypothetical item, four clients have had parathyroidectomy. One reports a sore throat, one has a hoarse voice unchanged since recovery, one reports perioral tingling, and one is anxious with new neck swelling and difficulty swallowing. The client with neck swelling and dysphagia is seen first because an expanding haematoma threatens the airway.

The client with perioral tingling is next, because it may signal falling calcium; check the latest result, assess for cramps or twitching and notify the prescriber. A stable hoarse voice and a sore throat are expected or lower-priority findings. Documentation should record wound and neck checks, voice quality, calcium trends and symptom reports.

Sources and further reading

MSD Manual Professional: Hypercalcemia. Postoperative calcium monitoring and prolonged hypocalcaemia requiring calcium and vitamin D after parathyroidectomy.

MSD Manual Professional: Hypocalcemia. Hungry bone syndrome after parathyroidectomy, perioral and peripheral paraesthesias, tetany, laryngospasm, seizures, QT prolongation and the role of magnesium.

British Association of Endocrine and Thyroid Surgeons: Primary hyperparathyroidism and surgery patient information. Recurrent and external laryngeal nerve injury, wound bleeding and temporary low calcium after surgery.

Anaesthesia (PMC): Management of haematoma after thyroid surgery, DAS/BAETS/ENT UK guidelines. Recognition of neck haematoma, bedside emergency equipment and structured wound opening; possible relevance to parathyroid surgery.