In vitro diagnosis of malignant hyperpyrexia syndrome

Malignant hyperthermia syndrome (MHS) is rare, inherited, and triggered by volatile anesthetics and depolarizing muscle relaxants. While potentially fatal, if recognized and treated early recovery is usual. However, the condition is often not recognized until an extreme increase in temperature develops with profound circulatory depression. In this stage the syndrome is irreversible, despite specific treatment with dantrolene. At present, the only reliable diagnostic test for susceptibility to malignant hyperthermia requires sampling of viable muscle for in vitro contracture tests with caffeine and halothane. Until our malignant hyperthermia diagnostic center was opened, such tests could not be performed in Israel. Since then we encountered a 22-year-old man who developed the partial picture of malignant hyperthermia syndrome during anesthesia for inguinal herniorrhaphy. He received dantrolene and recovered. 4 months later in vitro contracture tests with caffeine and halothane performed on biopsied muscle confirmed the diagnosis.