Malignant hyperthermia: clinical course and metabolic changes in two patients.

Two cases of malignant hyperthermia (MH) are presented. One patient was treated symptomatically for the first 6 h until she was given dantrolene. Her clinical course was complicated and the catecholamine and cortisol concentrations were still elevated 24 h after start of treatment. In the second patient an early diagnosis was made and treatment promptly instituted. Only minor endocrine-metabolic changes were seen in this patient. However, in spite of the early successful treatment with dantrolene the MH reaction recurred 12 h after the initial symptoms. These two cases demonstrate the importance of early treatment including dantrolene. Successful treatment with dantrolene does not, however, preclude a recurrence of MH, and thus subsequent doses of dantrolene should be given.