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Anesthesia and FSHD
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Anesthetics People with neuromuscular disorders must take great care if they are to have a local or general anesthetics. Even someone with very mild, or non-existent symptoms, or someone who has a family history of a disorder, needs to let the anesthetist know well in advance so that tests can be carried out and proper care after the operation can be arranged. Many people are afraid of having an anesthetics, mainly through ignorance, but when we look at the rate of complications and even deaths arising from anesthesia we see that it is, in fact, very safe. This safety is the result of a thorough understanding of the patient’s medical condition with a careful assessment before the operation, marked technical improvements in monitoring facilities during the operation, and the provision of good recovery facilities such as High Dependency Units (HDU) and Intensive Care Units (ICU). Patients with neuromuscular disorders (NMDs) deserve special attention when it comes to anesthesia because many of the agents used (gases and chemicals) have effects on both muscle and nervous tissue. The main areas of concern are how the anesthetics agents will affect the muscle and nervous tissue including the heart, which is, itself, a muscle. A skeletal deformity such as scoliosis, or curvature of the spine, can also affect the way the patient responds to anesthesia so it is important to consider that, too. Anesthetics and the heart An article printed in the Winter, 1995, No. 20 edition of The Search, showed how people with NMDs could sometimes have associated heart disease. This can occur as a cardiomyopathy, when the heart muscle doesn’t work effectively, or as a defect in the way the electrical activity of the heart is transmitted, a conduction defect. The anesthetics vapors—the smelly agents such as ether and halothane that are inhaled—can reduce the effectiveness of the heart’s muscle contractions and also aggravate any conduction defect. The vapors are all slightly different from each other, some having more effect on the heart than others. So it is important that the anesthetist makes a good assessment of the heart’s condition before the operation which would include the level of physical activity that the patient can manage, and an ECG. Occasionally a more extensive assessment is needed. Anesthetics and breathing Doctors need to measure how weak the patient’s muscles are, usually by assessing the amount of physical activity that the patient can perform, and by taking a blood test to measure levels of a muscle enzyme, creatine kinase (CK). Any anesthetics agent that affects the muscles will also affect the muscle we use to breathe. Strong analgesic or sedative agents will affect these muscles indirectly, and muscle relaxants will have a direct effect on them. As breathing (or respiration) may already be difficult for patients with NMDs, these drugs should be used cautiously, and monitoring of breathing after the operation is absolutely essential. As a result, the patient is usually best cared for in a High Dependency Unit or Intensive Care Unit immediately after the operation. The muscles used for swallowing can also be affected which is another reason why good post-operative care is important. Muscle relaxants Muscle relaxant drugs should only be used if essential because they tend to have a more profound and prolonged effect in NMD patients compared to other patients. One type of muscle relaxant, called suxamethonium, should usually be avoided. It causes the release of potassium ions (K+) from the muscle tissue into the blood. In normal patients this is usually of little practical significance. In patients with NMD the muscle may normally leak K+ so that a further increase in the levels of K+ in the blood may cause abnormal heart rhythms. A pre-operative blood test to check K+ levels is therefore important. Local anesthetics A local anesthetic works by preventing the normal electrical activity in the nerve around which the anesthetics agents are placed. For minor procedures, such as stitches for cuts, they are probably the first choice for patients with NMD because they have few, if any, side effects. However for major local anesthetics techniques, e.g. spinal or epidural, careful assessment of the patient is needed and the type of NMD considered well before the operation. Changes in body temperature and pre-operative ‘starvation’ Patients with NMD do not tolerate changes in body temperature or the starvation often associated with anesthesia or surgery as well as normal patients, so steps need to be taken to minimize these problems by keeping the patient warm and well hydrated using drips. Malignant hyperthermia (MH) and Central Core disease Malignant hyperthermia (MH) is an inherited disorder, which causes an unexpected, sometimes fatal, reaction in the patient to certain anesthetic drugs. Because some patients with NMD have sometimes experienced similar problems during anesthesia, there have been claims that patients with NMD may also have MH. However, it is generally accepted that the only neuromuscular condition truly related to MH is Central Core Disease (CCD), although this is not always the case. Patients with CCD should be considered potentially susceptible to MH unless proved otherwise by a special type of muscle biopsy, which screens for MH. To sum up . . .
* * * * * * * * * An Overview of Anesthetic Concerns for Persons Diagnosed with FSHD Introduction I became part of the FSHD family when my daughter was diagnosed with FSHD at Duke University’s Muscular Dystrophy Association Clinic in 2003. Since that time, I have liaised with the officers of the FSH Society, genetic specialists at Duke University and other academic and medical centers in order to better understand the disease and its progression. While I have come to understand that, as yet, we cannot change FSHD genetics or cure FSHD, I do believe that some potentially life threatening situations for persons with FSHD can be minimized or eliminated. After a recent trip with my daughter, by ambulance, to an emergency room (ER) for a suspected seizure, I have come to the conclusion that every person with FSHD and their caregivers should be prepared to give details about FSHD and key potential anesthetic complications associated with it, while in the ER, the intensive care unit (ICU) or prior to elective surgery. This article will explain and examine several key anesthetic concerns for persons with FSHD and is intended to encourage those with FSHD (or their caregivers) to be proactive in providing information about FSHD to those providing medical care. It is not intended to serve as medical advice. Anesthetic concerns Even within the high quality medical care system in America, not all medical staff—including nurses, residents, and interns—are familiar with muscular dystrophies and neuromuscular diseases.
The basic anesthetic concern for all persons with neuromuscular diseases, including those with FSHD, is that the respiratory system, due to a weak diaphragm muscle or chronic response to elevated carbon dioxide levels, can be additionally compromised with oral, intravenous or inhaled drugs (or even the inappropriate use of oxygen). For example, muscle relaxants, like valium, can suppress respiratory function by compromising the diaphragm, and opioids (for pain), while not directly affecting the lungs, can have central (i.e., brain) effects that can compromise the respiratory system. Respiratory insufficiency can occur in all persons with FSHD. However, evaluation of the symptoms and signs of respiratory insufficiency during routine clinic visits is probably more important in patients with moderate to severe FSHD. The first pulmonary visit can be used as a baseline tool; subsequent visits can be used to determine if pulmonary function is changing over time.
Regular monitoring of respiratory function is important because insufficiency can occur gradually, over a long period of time without clinical signs. Symptomatic respiratory insufficiency can initially be managed with night time non-invasive pressure support like a Bilevel Positive Airway Pressure (BiPAP) machine which helps get more air into the lungs. In severe cases, FSHD patients may require the use of invasive mechanical ventilation. In standard practice, trauma, ER, ICU, surgery and anesthesiology settings, care should be taken not to suppress respiratory drive with narcotics. Oxygen supplementation can be detrimental to patients with hypercarbic (high CO2) respiratory failure and lead to worsening (i.e., higher) carbon dioxide (CO2) levels. Oxygen should generally not be administered unless BiPAP or similar ventilatory support is also being used.
Your physician and pulmonologist can help you periodically monitor CO2 levels in the office or evaluate pulmonary function in the hospital, or even by a nocturnal oxymetry study. The timing for the periodic monitoring of pulmonary function will be determined by the results of the baseline visit, any new clinical signs, you, your pulmonologist and your neurologist may discover. Elective surgery, surgery for dentistry, or surgery that allows some planning time Anyone having surgery should be aware of the risks associated with the surgical procedure and/or complications that may arise during and/or after it. While certain risk factors are increased in people with FSHD who undergo anesthesia, each individual is different and reactions to anesthetics may be different. As with all medical procedures, you should talk to your physician about the specifics of your case and what you should anticipate and hopefully have baseline data available for physician review – like pulmonary function data. The following is a brief description of complications that may occur among people with FSHD who have surgery. Complications from anesthesia While this list is not exhaustive, complications in patients with FSHD who have had anesthesia during surgery can include the following:
Some of these complications appear to be related to the symptoms, severity and stage of FSHD, while other complications, such as respiratory or heart problems, appear to be related to secondary conditions. For example, while rhabdomyolysis appears to be a complication related to NMD symptoms, breathing problems are most often associated with a respiratory problem that is secondary to the muscle weakness caused by the disease process. There are no definitive ways to completely alleviate all risks; however, there are several precautions, like pre-operative testing, that physicians can take to lessen the likelihood of these complications. Pre-operative testing One way to prevent or alleviate complications from surgery in individuals with FSHD is through pre-operative testing. These tests may or may not be done based upon the information already contained in your medical records (i.e., symptoms and severity, whether or not you are known to have heart or respiratory problems, etc.). If your physician does not have sufficient information, she/he may run a variety of tests (see below for examples of preoperative tests) to determine:
For patients with FSHD who have not had these tests performed earlier, these pre-operative tests are recommended:
Identification of a potential problem to medical persons Without a caregiver present or the ability to speak coherently, medical personnel may not know that you have FSHD. FSHD patients should take care with their advanced medical directives and health care proxies to be sure that the “do not resuscitate clause” does not put them at risk. Use of a bracelet, necklace, etc., from MedicAlert (or a similar service) will notify medical personnel to potential problems associated with FSHD. A USB flash memory drive with medical files (in PDF or MS Word formats) is an alternative way to transport medical information in a purse or pocket. On the other hand, use of a bracelet or necklace in adolescents can be problematic because, at this age, it identifies the person afflicted with FSHD to a nontargeted (e.g., non-medical) audience. It may be possible, in lieu of a bracelet, to carry such identification card in the wallet or purse. Conclusions
Editor’s note: This parent raises important concerns especially in his call for more information to provide medical personnel. The FSH Society will prepare a fact sheet to be carried by patients and their families. References: 1. Klingler W, Lehmann-Horn F, Jurkat-Rott K., “Complications of Anaesthesia in Neuromuscular Disorders.” Neuromuscul Disord. 2005, Mar;15(3):195-206. Epub 2005 Jan 28. Department of Anaesthesiology, Ulm University, Albert-Einstein-Allee 11, 89069 Ulm, Germany. 2. Halsall and Ellis. Anesthetics, Academic Unit of Anesthesia, St. James University Hospital, Leeds, The United Kingdom, FSH Watch, Spring 1998. 3. Respiratory Therapeutics in Neuromuscular Disease, NMDinfo.net at http:// disability.ucdavis.edu/report_retrieve.php? Report=0029x accessed November 15, 2007. 4. Personal communication: Perez, D. President and CEO, FSH Society, 2007. 5. Personal communication, Abresch, RT. Director of Research, Center for Neuromuscular Disease at UC Davis, Davis, CA, 2007. * * * * * * * * * Links to recent articles about anesthesia in FSHD
* * * * * * * * * Health Information About Facioscapulohumeral Muscular Dystrophy (FSHD) * * * * * * * * * The information on this website is provided for general informational and educational purposes only. The FSH Society and this website do not provide medical advice or recommendations. Licensed physicians and other medical professionals who are familiar with an individual’s specific health situation should be consulted for diagnosis and treatment of Facioscapulohumeral Muscular Dystrophy and any other medical conditions. Neither the FSH Society nor any contributor to this website can be liable or responsible for any result derived from the use of this material. TEXT SIZE
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Anesthetics