Q: My 10 year-old son recently died from malignant hyperthermia. He was very healthy except for his recurrent tonsillitis for which his ENT suggested a tonsillectomy to prevent Rheumatic Fever. Unfortunately, during the operation he suddenly developed very high grade fever, generalized stiffness and irregularities in heart rhythm. He expired on the operating table. The two anesthesiologists who attended to him told me he had a full-blown case of malignant hyperthermia. Malignant hyperthermia is a preventable disease and there is an antidote for it. I am presently having an advocacy to make the antidote available in all hospitals. I am wondering if you can run something in your column to increase the awareness of the public regarding this condition and possibly save some lives.

--Nune B. Nalgomera, M.D., Las Piñas City

A: Malignant hyperthermia syndrome (MH) is an uncommon serious disorder of muscles that is triggered by the administration of drugs, usually agents used in general anesthesia. The condition is characterized by hypermetabolism and sustained contraction of skeletal muscles that results in rapid rise of temperature (as fast as 1-2 degrees Celsius per minute) to 40.5 degrees Celsius or higher, muscle rigidity or stiffness, and a variety of metabolic abnormalities.

MH is an inherited disorder. It is an autosomal dominant trait, meaning it requires only one parent carrying the gene for the disease for a child to inherit the condition. Its estimated incidence rate is 1 in every 15,000 pediatric and 1 in every 50,000 adult general anesthesia.

MH usually occurs in a previously healthy individual, as in your son. Often, it occurs in people who are undergoing general anesthesia for the first time, but it can also occur in individuals who have had no reaction to a previous general anesthesia. MH typically occurs in the operating room, but sometimes it develops when the patient is already recovering from anesthesia. General anesthetic drugs that have triggered MH include isoflurane, desflurane, enflurane, sevoflurane, methoxyflurane, cycl-propane halothane, and succinylcholine. MH, however, is not associated with drugs used for local or regional anesthesia.

MH is highly fatal if untreated; most patients die of cardiac arrest secondary to the metabolic abnormalities associated with the syndrome. Fortunately, there is an available drug, dantrolene, which reverses the metabolic disorders of MH. When diagnosed and treated correctly, the mortality rate from MH is practically zero.

Dantrolene, however, has one drawback. It is rather expensive, that is why many hospitals in the Philippines do not stock the drug in their operating rooms. This is sad because MH is a treatable disease and deaths from it should never occur. All facilities, where general anesthetics are administered, should stock a minimum of 36 vials of the drug, along with the other drugs and devices necessary to treat MH, even if the need for them is rare.
 
I am sure glad that you are actively advocating for the provision of dantrolene in all hospitals and clinics that administer general anesthesia throughout the country.

To prevent MH, people who are going to have surgery under general anesthesia should tell their doctor if anyone in their family has had malignant hyperthermia or has died without any apparent cause during anesthesia. This should alert their doctor into perhaps ordering some test such as the halothane-caffeine contracture test that can tell whether a person is susceptible to the condition or not. Additionally, it can help the anesthesiologists decide on what anesthetic agent to use and alert him/her on things to watch out for during surgery.

(Note: email inquiries on health matters to: medical_notes@yahoo.com or wellbeing@mb.com.ph.)