[Comments on anesthesia procedures in mitochondrial encephalomyopathy]

Mitochondrial encephalomyopathies (MEMP) are rare diseases caused by a disturbance of the mitochondrial chain of respiration. This prevents pyruvate from being completely integrated into the tricarboxylic acid (Krebs') cycle, and hence there is an accumulation of lactate. Histologically this is marked by the appearance of "ragged red fibres" in the light microscope which, in the electron microscope, are eventually recognised as typical accumulations of pathological mitochondria. The clinical pattern can vary greatly and ranges from ophthalmoplegia via mainly myopathic to encephalopathic forms. The pattern of signs and symptoms enables subclassification into three main syndromes (10): The Kearns-Sayre syndrome (KSS), "myoclonus epilepsy with ragged red fibres syndrome" (MERRF) and "mitochondrial myopathy, encephalopathy, lactic acidosis and strokelike episodes syndrome" (MELAS). Intermediate types, however, are frequent. Furthermore, quite a large number of other syndromes such as the "Toni-Fanconi-Debré syndrome" can be classified among the group of mitochondrial encephalomyopathies.--The patient must be classified as a risk patient. Disturbances of cardiac conduction may require a transient or permanent pacemaker. Increase in oxygen requirement must be avoided to prevent increase in lactate levels and development of lactate acidosis. The severity of the myopathy makes it necessary to exercise caution in the use of benzodiazepines and long-term relaxants. When using local anaesthetics one should consider both their negative dromotropism and the resulting reduction of the epileptic threshold. There is a relative contraindication for spinal and epidural anaesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)