Diagnosis and management of susceptibility to malignant hyperthermia in pregnancy.

A case of susceptibility to malignant hyperthermia, diagnosed by muscle biopsy during the first trimester of pregnancy, is presented. Pertinent medical history that might raise this suspicion is reviewed. The pathophysiology of malignant hyperthermia is discussed. Recent reports documenting the placental transfer of dantrolene and complications associated with dantrolene administration during labor are described. The pharmacology of dantrolene sodium is presented. Guidelines regarding the management of labor and delivery in patients susceptible to malignant hyperthermia are outlined. Suggestions for counseling patients and their children with this syndrome are reviewed.