Charcot-Marie-Tooth Disease and Anesthetics

by Linda Crabtree with suggestions from Dr. Greg Carter

So many of you call us a couple of days before you are scheduled for surgery, worried about anesthetics that I thought it would be a good idea to write something that you can read and heed.

Before you have your operation:

1. Make sure your doctor knows you have Charcot-Marie-Tooth disease and that s/he understands it. Most doctors don't know very much about neuromuscular disorders because they simply aren't taught well in medical school unless s/he goes for extra training as a neurologist and then it is all mixed in with about 40 other neuromuscular diseases.
2. Make sure your doctor has the list of drugs you should not take because they could make your CMT worse.
3. Please make sure your doctor is totally familiar with the drugs you do take, even the over the counter remedies. If he doesn't know everything you take (and you may have to help him with some of the stuff especially if herbal or new) it could be a problem if he gives you something during an operation and doesn't know what else you are taking.
4. Make sure your doctor knows about any allergies you may have to drugs or anything else.
5. Make sure your anesthetist knows that because you have CMT your breathing may be impaired due to partial paralysis of your diaphragm. Your phrenic nerves that help activate your diaphragm could be affected by your CMT which means that you do not breathe well. This could also mean that you are not able to breathe out well enough and cannot expel the proper amount of CO2 and end up with CO2 poisoning. Oxygen will not help this condition because supplemental oxygen saturates your blood and brain with oxygen, making it lazy (kind of like being stuffed after a big meal), and this actually suppresses your central (brain and brainstem) drive to breathe (i.e. your brain says, "Hey, I've got all this O2, why should I breathe.") Thus you start breathing less and you start retaining CO2. The CO2 is already in your blood but by not breathing well you don't get rid of it. If you do have too much CO2 in your bloodstream you'll probably have a whopper of a headache. Sitting in an upright position, arms up or over your head if easier to breathe that way, and nice long, slow deep breaths will do the trick. If this is not possible, a ventilator works but is only needed if you can't breathe on your own. There has been a lot of research done on CMT and breathing and the medical journal articles are available from CMT International.
6. When at home, if you experience a bad headache, especially in the front of your forehead, upon awakening, you might consider having your breathing checked. This will entail having your maximum inspiratory pressure (MIP) taken and your maximum expiratory pressure (MEP) taken both sitting and lying down. It is lying down that most of us have a problem reaching the maximum expiratory pressure that most people can develop, because our breathing muscles are weak, and lying down we do not have the added benefit of gravity to help us move our diaphragm.
7. When you are going to go into surgery make sure your anesthetist knows
   • that you are to be kept warm at ALL times
   • that your breathing tests should be done before you go in for surgery and the anesthetist and respirologist know of any possibility of complications
   • that you should be kept under anesthesia as lightly as possible and for as short a period as possible
   • that succinylcholine has been looked into as the possible cause of a problem for us, and while it did not cause a problem for the majority of people used in the research, if it can be avoided, it's a good idea
   • that Charcot-Marie-Tooth disease is a neuromuscular disorder which affects not only the peripheral nerves but also the autonomic nervous system. There have been cases where a person's breathing has not been tested before surgery; they have been put under using the normal amount of anesthetic given an adult, and it has been difficult to bring these people back out of the anesthetic and some of them have gone on a respirator afterwards. This can definitely be avoided by educating the anesthetist BEFORE surgery
   • that after surgery, proper toileting should be done. Toileting is a word that anesthetists use for moving around, coughing, deep breathing, expelling mucus and even vomiting to clear the system of the residue of anesthetics. Make sure you talk to your anesthetist about all of this and that he is aware that you may need special care after surgery to get you back to your old self as far as breathing goes.
   • You can help yourself by trying to be as active as possible after surgery by standing if possible, walking, moving, doing whatever possible to keep your lungs going and the air getting right to the bottom. On some occasions lower lobe pneumonia has developed in people with CMT because they breathe shallowly in the first place, and with the residue of anesthetics, it is not easy for CMT people to clear their lungs. Some people with CMT lose their cough reflex. If you've lost your cough reflex, which means you really can't get behind a good cough and bring stuff up from your lungs, you have to make sure that your doctor, your surgeon and your anesthetist know about this as it could mean you need suctioning after major surgery.

It is wonderful what anesthetics have done to make all kinds of surgery possible and surgery means that certain aspects of our CMT can be treated. Because anesthetics involve our whole body, but mainly our lungs, it is very important for anyone with CMT to make sure that their breathing is checked BEFORE any surgery, that your doctor, your surgeon and your CMT specialists are aware of your CMT, of any drugs that you should not be given, of the fact that you could be sensitive to adult doses of anything, of any allergies that you have, and the fact that your breathing could very well be compromised as research has proven that over 90 per cent of people with CMT have some kind of breathing related problem.