Malignant Hyperthermia - 8
The Caffeine-Halothane Contracture Test (CHCT)

  • the current "gold standard" test for MH.
  • recently standardized in North America
  • the usual biopsy site is the quadriceps muscle (vastus lateralis or medialis)
  • Because of the size of the biopsy (2 Grams), it is recommended that patients weigh at least 20 kg. Most centers will not biopsy patients < 5 yrs old.
  • 2 to 3 months should have elapsed since the most recent (presumed) MH episode
  • anesthesia for biopsy
    • use nontriggering agents
    • regional anesthesia often used (nerve blocks or neuraxial block)
    • avoid direct infiltration of muscle with local anesthetic
  • dantrolene should be avoided
  • the muscle tissue should be handled as little as possible and not stretched
  • the test should be performed within 5 hours after the biopsy
  • costs approximately $6,000 - $10,000 (covered by most US health insurance companies)
The muscle biopsy and the CHCT should be performed at centers with appropriate familiarity and expertise.

Greg Gordon MD