Dear
This disorder makes a person susceptible to developing a chain reaction of symptoms (a syndrome) called malignant hyperthermia (MH). (Don’t be over concerned about the word “malignant” – MH has nothing to do with cancer.) MH occurs when a susceptible individual is given the drugs that “trigger” MH. The triggering drugs are: volatile inhalation anesthetics and succinylcholine, a muscle relaxant.
The reaction, which may (but does not always) occur, includes a variety of symptoms: muscle rigidity; dramatic changes in the acid content of the blood (which can cause irritation to the heart and possible cardiac arrest); increased amounts of carbon dioxide expelled by rapid and deep breathing (hyperventilation); breakdown of muscle, as indicated by very dark urine; and high body temperature (a late sign).
This syndrome is reversible if the operating team is prepared to act quickly. And, the severe problems associated with the syndrome are preventable if doctors know in advance of their patient’s potential MH susceptibility and take certain precautions.
Although MH is uncommon in the general population, the odds are quite high for family members of known susceptible patients to also have the trait. Most susceptible parents transmit the trait to about half of their offspring. It’s very important to note that more than 50% of MH-susceptible patients had general anesthesia on at least one occasion (uneventfully) before they even knew they were susceptible. You should not assume you are safe because you have had uneventful anesthetics.
The enclosed pamphlets are published by the Malignant Hyperthermia Association of the United States (MHAUS), a non-profit educational organization that provides a variety of information materials about MH and what you can do.
Right now there are several steps you should take:
Ø Notify your own doctors about your potential susceptibility. MHAUS can provide you with literature to give them.
Ø Contact hospitals in your area to be sure that they stock the antidote drug, dantrolene sodium for injection, and that they are prepared to care for your family in an emergency. MHAUS has a form letter you can use for this purpose.
At present, there is only one accurate diagnostic test for MH, and it involves having a muscle biopsy. MHAUS can send you more information about the test and a list of the testing sites in the United States which perform it by contacting: MHAUS, PO Box 1069, Sherburne NY 13460-1069 / 1-800-986-4287.
If you establish that you are, indeed, carrying the MH gene, you should talk with your doctor about registering yourself with the North American MH Registry of MHAUS as an MH-susceptible individual. You may contact the Registry at the University of Pittsburgh Children’s Hospital, Anesthesiology Dept, Room 7499, 3705 Fifth Ave at DeSoto St, Pittsburgh, PA 15213-2583 / 412-692-5464.
Sincerely,
Enclosures