Great progress in anaesthetic techniques has resulted in elimination or significant reduction of complications connected with the disease, operation technique or anaesthesia. However, sometimes a rapid increase in systemic metabolism occurs immediately after induction of anaesthesia and it may end in the patient's death. This syndrome defined as malignant hyperpyrexia (MH) was described for the first time by Denborough and Lovell (2). They reported 10 deaths of this type in one family. Later it was noticed that some patients may develop MH after inhalation anaesthetics or suxametonium. MH was observed more frequently in several groups of patients. It occurs rarely--1 to 15,000 cases after anaesthesia in children and 1 to 50,000 cases after anaesthesia in adults, but its sudden and rapid development becomes a great clinical problem.