Anaesthetics and muscle wasting conditions

People living with a muscle wasting condition, or with a family history of one, may need extra checks or precautions when having an anaesthetic. This is because there’s a higher chance of having complications from some anaesthetic and sedative drugs due to the way some muscle wasting conditions affect how the body responds.

It’s therefore important to tell your healthcare team about your condition or family history before having an anaesthetic. You can speak to them about what type of anaesthetic they might give you, and the benefits and risks.

An anaesthetic stops you feeling pain when you’re having a medical procedure or operation. There are three main types of anaesthetic – local, regional, and general. You may also be given sedation, alongside an anaesthetic, to help you feel calm during the procedure.

A doctor who specialises in giving anaesthetics is called an anaesthetist. You may see an anaesthetist if your procedure involves a general anaesthetic or sedation.

Local anaesthetic

A local anaesthetic numbs a small area of the body. It can be an ointment, a spray, drops, or an injection. You will remain awake but will not be able to feel any pain in that area.

Local anaesthetics are safe for people with muscle wasting conditions.

You can read more about local anaesthetic on the NHS website.

Regional anaesthetic

A regional anaesthetic is delivered through an injection and numbs a larger area of the body. It may be a spinal anaesthetic, epidural anaesthetic, or nerve block. You will remain awake but will not feel any pain in that area.

Regional anaesthetics are less likely to cause complications than general anaesthetics. They’re generally safe for people with muscle wasting conditions; however, they may not be suitable for everyone. If you’re having a regional anaesthetic, your healthcare team will check for any problems before, during, and after the procedure.

General anaesthetic

With a general anaesthetic, you will be completely asleep and not able to feel anything. You may have the anaesthetic through an injection into a vein, or as a gas you breathe in through a mask.

Many people with muscle wasting conditions are sensitive to general anaesthetics. An anaesthetic injection may be less likely to cause problems than gas. For both types, your healthcare team will check for any problems before, during, and after the anaesthetic.

Ask the anaesthetist which type of general anaesthetic is suitable for you.

You can read more about general anaesthetic on the NHS website.

Sedation

Sedation uses drugs (sedatives) to make you feel sleepy and relaxed. You will not be completely asleep, but often your memory of the procedure afterwards will be hazy. You may have a sedative on its own or with a local or regional anaesthetic.

People with muscle wasting conditions may be more sensitive to sedatives and may need a lower dose. If you need a sedative, your healthcare team will check for any problems before, during, and after the procedure.

Other drugs

For some operations, the anaesthetist will use a drug that relaxes the muscles. People with muscle wasting conditions usually need a lower dose. The muscle-relaxing drug suxamethonium (also called succinylcholine) is not suitable for people with muscle wasting conditions.

Pain relief is used after a major procedure or operation. People with a muscle wasting condition may be more sensitive to a type of strong painkiller, called opioids. Examples of opioids include morphine and codeine. Your healthcare team may offer you another type of painkiller or a regional anaesthetic. If you need an opioid, your healthcare team will give you a smaller dose and check you regularly.

Heart and lungs

General anaesthetics can affect how your heart and lungs work. The anaesthetist monitors this during the procedure to make sure people are safe and well.

People with muscle wasting conditions may have existing heart and lung problems. As a result, they may need extra checks and care when they have a general anaesthetic or some types of sedation.

If you need a general anaesthetic or deep sedation, you should always have them in a hospital with a post-anaesthetic or intensive care unit.

Malignant hyperthermia

People with certain genetic changes are sensitive to general anaesthetic gases you breathe in. They are also sensitive to the muscle-relaxing drug suxamethonium (succinylcholine).

Having these drugs can lead to malignant hyperthermia. Malignant hyperthermia causes a very high body temperature, fast heart rate, muscle cramps, and injury. In some cases, it can be life-threatening.

People with changes in the RYR1, CACNA1S, or STAC3 genes have a higher chance of getting malignant hyperthermia. But some people without these gene changes may also get it.

If you’re at risk of malignant hyperthermia, or if you have a family member that is at risk, your doctor will offer you another type of anaesthetic that is safe for you. It’s important to talk to your surgeon about this before you go into hospital. They may need to arrange for special equipment in advance.

Anaesthesia-related rhabdomyolysis

Some people with muscle wasting conditions are at risk of anaesthesia-related rhabdomyolysis. This is an uncommon but serious complication of anaesthesia. It causes muscle breakdown and high levels of potassium in the blood. If it’s not treated quickly, it can be life-threatening.

General anaesthetic gases or suxamethonium (succinylcholine) can sometimes cause rhabdomyolysis. If you’re at risk of this complication, your doctor may offer you a general anaesthetic injection instead.

It’s important to tell your anaesthetist and surgeon that you have a muscle wasting condition.

Before the procedure, you should see the anaesthetist or another member of the healthcare team. They may arrange some tests to check your heart, lungs and overall health. Tell the team if you are taking steroids, as they may need to arrange for you to have extra steroids during and after the procedure.

The healthcare team will explain which types of anaesthetic are suitable for you, as well as the benefits and risks of each type.

The anaesthetist will look after you during the procedure. They will make sure you are coping well with the anaesthetic.

After a general anaesthetic, the healthcare team will keep checking you for 24 hours. This is to make sure you’re recovering well from the anaesthetic drugs.

Some people may need a machine called a ventilator. This is to help with breathing for a short time after the procedure. Some people might have extra care in a post-anaesthetic or intensive care unit. They may stay here until they’re well enough to move to a general ward.

• Tell your anaesthetist and surgeon that you have a muscle wasting condition or a family history of one. It’s important to do this even if you do not have any symptoms.
• Your healthcare team should see you before the procedure. This is to check your health and find out how your muscle wasting condition affects your body.
• Ask your healthcare team about the benefits and risks of the procedure and anaesthetic.
• Ask your healthcare team where you will have the procedure. If you’re having a general anaesthetic, this should be in a hospital with an intensive care unit (ICU) if possible.
• Think about carrying an alert card or a medical alert bracelet. You can also use a medical information app on your smartphone. This can give useful information about your condition to medical staff, especially in an emergency. You can order or download condition-specific alert cards for some conditions from our alert card page.