Muscle Weakness In Children And Malignant Hyperthermia
If a child has muscle weakness, either diagnosed or undiagnosed, the parents must be aware of a condition called Malignant Hyperthermia. Recently, I met with two parents who have a child with undiagnosed muscle weakness. They are intelligent, caring parents who have sought doctors’ opinions in leading medical centers. Yet when I talked about the need for a muscle biopsy using a local anesthetic, rather than a general anesthetic, they looked puzzled. No physician had ever told them about Malignant Hyperthermia and the possible danger to their daughter if she were to be given a general anesthetic. This was of great concern to me since the doctors claimed to be neuromuscular specialists.
I explained to the parents that if certain anesthetics are used in some muscle disease patients that an extremely high temperature and tightness of the jaw may result, as well as other dangerous symptoms. The anesthetics to avoid are: succinylcholine, halothane, enflurance, isoflurance, and sevoflurance or others related to them. A board-certified anesthesiologist, who is aware of the disorder and the risks, can take precautions if a general anesthetic must be used. In addition, the anesthetic machine to be used for the surgery should be flushed out with ten liters of air or oxygen for twenty minutes, either the night before or several hours prior to use. This is to get rid of any anesthetics remaining from previous use.
Patients with central core disease and Duchenne muscular dystrophy are particularly at risk to develop Malignant Hyperthermia. Even if a previous anesthestic has been without incident the next one could be fatal. A family history is extremely important to determine if other family members have had problems with anesthetics.
The Malignant Hyperthermia hotline is at 1-800-644-9737. They can be contacted if there are questions and a physician is always on-call. I also caution parents who have an at-risk child to purchase a Medic-Alert bracelet that notes the problem. They can be contacted at 209-634-4917.
Charlotte E. Thompson, M.D.