A rare case of malignant hyperthermia in the Indian subcontinent

We would like to report the first case of malignant hyperthermia in India. A 9-year-old boy with a left thalamic glioma was scheduled to undergo craniotomy and tumour decompression. We induced anaesthesia with sevoflurane and placed a 6.0-mm internal diameter cuffed tracheal tube (Smiths Medical International Ltd., Hythe, Kent, UK) using vecuronium for neuromuscular blockade. We maintained anaesthesia with an oxygen ⁄ air ⁄ sevoflurane mixture with a calculated minimum alveolar concentration of sevoflurane ranging from 0.6 to 0.8. Thirty minutes postinduction, before skin incision, the child’s end-expiratory carbon dioxide partial pressure rose from 3.7 to 14 kPa, which persisted even with hyperventilation. There was a contemporaneous rapid increase in the core body temperature to 39.8 C and a tachycardia. The patient developed disproportionate rigidity of his extremities despite maintaining adequate neuromuscular blockade. An arterial blood gas analysis at this point showed respiratory acidosis. At this stage, we considered the diagnosis of malignant hyperthermia. We discontinued sevoflurane and manually ventilated the patient’s lungs with a Bain’s breathing system and a high fresh gas flow. We maintained anaesthesia with a propofol infusion and surgery was abandoned. Surface cooling and cold intravenous fluids were administered to treat hyperthermia. Within 30 min of stopping sevoflurane, muscle rigidity improved, and gradually body temperature and heart rate returned to normal. Arterial blood gases at this stage showed correction of acidosis. Blood investigations revealed a raised creatine kinase value of 11635 IU. We were able to terminate anaesthesia and the child recovered uneventfully. Two days later, he underwent uneventful tumour excision under ‘non-triggering’ general anaesthesia. An in-vitro contracture test could not be performed, as this laboratory facility is not available in India. The diagnosis of malignant hyperthermia is based on clinical presentation, contracture testing and genetic studies. Larach described a grading scale using clinical indicators for determining the malignant hyperthermia raw score [1]. This score has been considered a useful research tool for malignant hyperthermia based on clinical findings and biochemical tests [2]. The total score in our patient was 88 (malignant hyperthermia rank 6) indicating a high possibility of malignant hyperthermia as the clinical diagnosis. We could not find any reports of malignant hyperthermia occurring in the Indian subcontinent. Epidemiological studies are difficult in this rare condition; however, regional variations in the incidence are evident in the Asian population, being more common in East Asia [3]. Drug exposure and other environmental factors can influence the development of an episode of malignant hyperthermia [4]. This report also highlights the need for availability of diagnostic tests in India, considering malignant hyperthermia as a rare differential diagnosis for hypermetabolic states occurring during general anaesthesia. The reason why this entity is uncommon here requires evaluation and a malignant hyperthermia registry should be introduced for proper reporting of cases. Finally, the availability of dantrolene and guidelines for its use in India need to be addressed.