<prompt> Malignant hyperthermia is caused by all exceptThiopentone sodiumSuccinyl cholineHalothaneNone of the above  <response>: A Thiopentone sodium MALIGNANT HYPERTHERMIA is the clinical syndrome observed during GA associated with rapidly increasing temperature as great as 1degC5 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 meqkg; Dantrolene 2 mgkg 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. 