My mom had a reaction to anesthesia. She could not be wakened easily, developed a fever, skin was red, and Pretty sure her blood presure was low. Said she had "MH." She passed away last June so to get more details is not so easy. Anyway, I need to know if I am a carrier for this "MH"? I have two kids now and the one has needed to be put out differently due to this. What can I do?? Thanks. 

"MH" (Malignant Hyperthermia) is a very important, though rare, condition in which certain anesthetic drugs can trigger a life-threatening reaction. During an MH reaction, or "crisis", the metabolism of muscles is speeded up to an extreme degree, causing a rise in body temperature, increased consumption of oxygen, muscle stiffness, electrolyte disturbances, and, if untreated, death. MH is an inherited condition. Over the last decades, MH has gone from a mysterious condition without effective treatment, to something that, if recognized early and treated promptly should have a good outcome. The drug dantrolene is a specific and highly effective treatment for an MH reaction. Unfortunately, MH is still difficult to diagnose. The genetics are not straightforward. This means that the odds of you having inherited MH from your mother are not precisely known. And despite the advances in DNA technology there isn't an easy genetic test for it. The standard method of diagnosing MH in the relatives of those who have had an MH reaction is to take a piece of muscle and test it with one of the drugs that can trigger an MH crisis. The problem is you need quite a large piece of muscle, usually taken from the thigh in a surgical procedure that itself requires an anesthetic! Without a muscle biopsy and laboratory testing you cannot be sure that you or your relatives are "MH susceptible". The safe alternative to such testing is to simply assume that you have inherited the condition, and to proceed on that basis. Your anesthesiologist will use a "non-triggering" anesthetic, avoiding the drugs that might cause a reaction. The drugs to avoid are the halogenated inhalational anesthetics (gases) including: Halothane, Isoflurance, Sevoflurane, Desflurane, Muscle relaxant drug succinylcholine. MH has no known affect on everyday life and is only a potential problem if you are given a general anesthetic with triggering agents. Be sure to always tell your doctors about your MH history. It may be wise to acquire a Medic-Alert bracelet or wallet card with this information printed on it. 

My daughter does not sweat and has had to be removed from all sports activities at school. She is eleven years old and has epilepsy, neurofibromatosis which the MD feels is mild, is on several meds for seizures, but still has seizures. She also did not sweat normally prior to being on the seizure meds. My question is she is going to have a vagus nerve stimulator placed next week, with her inability to sweat is she predisposed to malignant hyperthermia? 

Thank you for your question. Your daughter has complex problems that must be very challenging for both of you to deal with. Your daughterﾒs inability to sweat is, as you know, a significant problem because sweating is one of the important ways of regulating body temperature. People who are unable to sweat are therefore at risk for heat stroke. It is not clear from your question what is the actual cause of your daughterﾒs anhidrosis or hypohidrosis. Epilepsy drugs are apparently one potential cause of this unusual problem. I wonder whether neurofibromatosis could be associated with changes in autonomic nervous function (the autonomic nervous system controls the function of glands, including sweat glands) which can impair sweating. You should ask your neurologist about this. Malignant hyperthermia, the other disorder you refer to, is a specific inherited disorder, in which certain anesthetic drugs trigger a dramatic increase in muscle metabolism. One of the signs of this uncontrolled increased metabolism is a raised body temperature (hence the term ﾓhyperthermiaﾔ). Other signs are increased heart rate, rapid breathing, and eventually muscle stiffness (rigidity). Malignant hyperthermia is associated with severe metabolic disturbances that if untreated very often lead to death (hence the description ﾓmalignantﾔ). Fortunately, malignant hyperthermia, is both rare, and if recognized early, treatable. The treatment is to stop the administration of the anesthetic agents responsible, and give a drug called dantrolene. Affected persons can receive a safe anesthetic by avoiding so-called inhalational anesthetic agents, such as isoflurane, sevoflurane and desflurane, and muscle relaxants like the drug succinylcholine. The implantation of a vagus nerve stimulatorﾠis a new way to treat epilepsy. Although we do not yet have any experience with this procedure in our center, I imagine that this will require a general anesthetic. Most patients do not sweat under general anesthesia. In fact, most patients in the operating room cool down, and have to be actively warmed, using methods such as the application of special warming blankets. In summary then, malignant hyperthermia is a distinct disorder which is unlikely to affect your daughter. She is more likely to cool off than heat up in the operating room. Her temperature should, however, be carefully monitored during the anesthesia and, especially, during the recovery period. Be sure to discuss your concerns with the anesthesiologist responsible for taking care of your daughter. If possible you should go over these issues with him or her well ahead of the date of the procedure.ﾠ