Acute laryngeal spasm

Abstract

A 45-year-old man presented to the emergency room with an acute episode of laryngeal spasm. He underwent emergency tracheotomy. He had recurrent episodes of generalised tonic-clonic seizures of 4 years' duration and was on phenytoin sodium 400 mg/day. The frequency of seizures had increased, requiring increasing doses of phenytoin. He had pallor, coarse facial features, gum hyperplasia (fig 1), nuclear cataracts, bilateral extrapyramidal rigidity and carpopedal spasm. Investigations showed macrocytic anaemia; hypocalcaemia, serum calcium 0.5 mmol/l (1.1-1.4 mmol/l); hyperphosphataemia 2.0 mmol/l (1.0-1.4 mmol/l); parathyroid hormone 5 ng/l (10-60 ng/l), 25-hydroxy vitamin D3 30 nmol/l (37.4-200 nmol/l), normal electrocardiogram and phenytoin 22 mg/ml (10-20 mg/ml). A plain cranial computed tomography scan showed bilateral basal ganglia and cortical calcifications (fig 2). In patients with hypoparathyroidism, phenytoin and other microsomal enzyme inducers can accelerate the hepatic inactivation of vitamin D and worsen the hypocalcaemia and its clinical manifestations, including life-threatening manifestations such as acute laryngeal spasm.

Hypocalcaemic laryngospasm in the emergency department

“…The symptoms of tetany may be mild (muscle cramps, paresthesias of the hands and feet) or severe (laryngospasm, carpopedal spasm and seizures) 1 5. Tetany is a common feature if the ionised serum calcium level falls below 1.10 mmol/l 1–5. In spite of severe hypocalcaemia, Trousseau's and Chvostek's sign may both be absent at presentation 1…”