Spinal cord injury-related thermoregulatory impairment masks a fatal malignant hyperthermia crisis: a case report

Malignant hyperthermia (MH) is a hypermetabolic disorder that can occur in genetically susceptible individuals exposed to halogenated anesthetics and succinylcholine. Spinal cord injury (SCI) above the sixth thoracic vertebra is associated with dysfunction of the sympathetic/parasympathetic nervous pathways, including thermoregulatory dysfunction, presenting as hypothermia in cold environments because of vasodilation and heat loss. This effect could mitigate or obscure an MH episode. Here, we describe development of a fatal MH crisis in a patient with SCI.

A 27-yr-old male patient with an SCI after fracture of the sixth cervical vertebra was admitted for spinal arthrodesis. Anesthetic medications included remifentanil, propofol, succinylcholine, rocuronium, and isoflurane. After the start of the surgery, muscular contractures resembling myoclonus were noted, which resolved with pancuronium administration. Four hours after the start of anesthesia, the patient presented with hyperthermia, hypercarbia, hypotension, muscle rigidity, arrhythmia, and cardiogenic shock, with metabolic/respiratory acidosis. Malignant hyperthermia was suspected and the treatment was started, but he developed cardiopulmonary arrest and died an hour and a half after the first cardiac arrest. Both parents were investigated and were found to have normal creatine kinase levels and positive in vitro contracture tests. His mother carried a variant in the ryanodine receptor type 1 (RYR1) gene (c.14918C>T), which is associated with MH.

Spinal cord injury-induced thermoregulatory dysfunction may obscure the early diagnosis of MH and lead to fatal outcome.