Hypocalcaemia

Acute severe hypocalcaemia most often occurs following extensive neck surgery e.g. for thyroid cancer. This emergency guide outlines a strategy to prevent this complication and to treat it and other causes of severe hypocalcaemia.

 

General examination

A full general examination is mandatory in the initial assessment of all endocrine patients. Look carefully at the neck for old scars in patients too unwell to recall whether they have undergone previous surgery.

Trousseau sign

Inflate a blood pressure cuff above the patient's systolic blood pressure, and wait for up to three minutes. If the patient develops carpopedal spasm, this is a positive Trousseau sign.

Note, to check for this sign properly, the cuff does need to remain inflated for significantly longer than usually necessary to check blood pressure, and both this, and the spasm may be uncomfortable for the patient.

Chvostek sign  

Tap the facial nerve, just in front of the ear, with the patient's mouth slightly open. If this leads to repeated twitching of the facial muscles, this is Chvostek positive.

Cardiovascular examination

Patients with severe hypocalcaemia may present with bradyarrhthmias which may lead to low output cardiac failure.

Respiratory examination  

Bronchospasm and laryngospasm causing respiratory distress or stridor may complicate acute severe hypocalcaemia.

Neurological examination  

Examine the patient carefully for any neurological deficits, in particular if there is a history of seizures.

Patients with hypocalceamia may also be hyper-reflexic.