Delayed Onset Malignant Hyperthermia in a Child with Previous Uneventful General Anesthesia: A Case Report

Malignant hyperthermia (MH) is a genetic disorder of skeletal muscles which leads to a progressive life-threatening hyperthermic reaction due to the use of Suxamethonium or Inhalational agents in anaesthesia. It is not commonly reported in Sri Lanka. The condition usually manifests in the initial exposure to the causative agents. A 9-year-old male child, who had 2 previous uncomplicated anaesthetic exposure, was admitted for an alveolar bone graft surgery. In the latter part of the surgery, the child developed features of malignant hyperthermia, following exposure to a volatile inhalational agent, isoflurane. Early treatment with dantrolene arrested the disease process and reduced the complications, even though he was treated in intensive care for several days. This case demonstrates that malignant hyperthermia can develop gradually, contrary to the typical rapid onset, even in patients with prior uneventful exposure to triggering agents. Early diagnosis and timely administration of dantrolene are essential to prevent life-threatening complications.