This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Anaesthesia
[{'content': 'Malignant hyperthermia is caused by all except \nSelect and explain. \nA. Thiopentone sodium, B. Succinyl choline, C. Halothane, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (A) Thiopentone sodium # MALIGNANT HYPERTHERMIA is the clinical syndrome observed during GA associated with rapidly increasing temperature as great as 1degC/5 minute.> Etiology: It is due to abnormality of Ryanodine receptor which is a calcium releasing channel of sacroplasmic reticulum. Causative agents of malignant hyperthermia> Muscle relaxant: Succinylcholine> Inhalational agents: Halothane (most common); Isoflurane; Enflurane; Desflurane; Methoxyflurane> Local anaesthetics: Lignocaine> Tricyclic antidepressants MAO inhibitors; Phenothiazines> Clinical features of malignant hyperthermia: Hyperthermia (T > 1 09degF); Increased end tidal CO2; Tachycardia, hypertension; Severe metabolic acidosis; Hyperkalaemia, increased creatine phosphokinase; Renal failure; DIC.> Treatment of Malignant Hyperthermia: Stop all anaesthetics; Control temperature; Sodium bicarbonate IV 2-4 meq/kg; Dantrolene 2 mg/kg repeated at every 5 minutes.> There is a fall in intraocular pressure with isoflurane, and isoflurane may precipitate malignant hyperpyrexia.> Halothane classically produces malignant hyperpyrexia in susceptible individuals. There is a reduction in intraocular pressure.', 'role': 'assistant'}]