GLP-1 RAs and Fasting Before Surgery

Safety during hand and wrist surgery Sydney

GLP-1 receptor agonists (GLP-1 RAs) are a class of weight loss medications that includes Ozempic, Wegovy, and Mounjaro. The number of Australians taking these medications has been rapidly increasing over the past few years.

If you take a GLP-1 RA and you’re having a surgical procedure, it’s important to be aware of how the medication can affect your preparation for surgery. Although it’s considered safe to have surgery while taking a GLP-1 RA, there are some considerations to keep in mind.

Why do people need to fast before surgery?

Before having general anaesthesia or deep sedation, patients usually need to fast for several hours beforehand. The most common recommendation is to stop eating 6 hours before the procedure. Clear liquids are still allowed until two hours before the procedure, and then the recommendation is to have nothing to eat or drink until after surgery is over.

Following these fasting recommendations is crucial in order to protect patients from one of the major dangers of undergoing anaesthesia. Once a person is anaesthetized, the contents of the stomach can flow back up through the esophagus towards the throat. From there, they can easily be inhaled into the lungs. This is known as aspiration, and it can cause a serious infection and can even be fatal.

To avoid the risk of aspiration, it’s important for your stomach to be empty at the time you go under anaesthesia.

How can a GLP-1 RA affect preparation for surgery?

One of the major effects of GLP-1 RAs is that they slow down the emptying of your stomach. This is a huge part of how these meds cause weight loss. By slowing down the passage of food through your stomach, they keep you feeling full for longer.

However, this same effect can also cause issues before surgery. Since the medication slows down the emptying of your stomach, the usual recommendations for fasting may not be enough. For most people, the stomach is completely empty after about 6 hours of fasting, which is why this is the usual period of fasting that’s recommended. However, for someone taking a GLP-1 RA, there could still be a significant amount of food remaining in the stomach after this period of time.

Do you need to stop taking your GLP-1 RA before surgery?

Given that GLP-1 RAs slow down the emptying of your stomach, it makes sense to wonder whether you should stop taking your GLP-1 RA before surgery. However, the current guidelines actually don’t recommend this. You should continue to take your GLP-1 RA as usual before your surgical procedure.

This is partly because stopping the medication wouldn’t necessarily be enough to keep you safe during surgery. It takes a while for stomach emptying to return to normal rates after stopping a GLP-1 RA. Even if you stopped taking the medication for a week before your procedure, your stomach might still be emptying at a slower rate than usual at the time of your surgery. Currently, there isn’t enough data to make a confident recommendation about how long the medication would need to be stopped to allow stomach emptying to return to its baseline rate.

In addition, GLP-1 RAs have other effects in the body besides slowing down the emptying of the stomach. For example, they also help to keep blood sugar under control. When a person stops a GLP-1 RA, their blood sugar levels may increase. High blood sugar levels can interfere with the body’s healing process, so this is not something you want to risk just before having surgery.

Instead of stopping the medication, you will need to follow a modified fasting protocol to help keep you safe during surgery.

How should you prepare for surgery if you’re taking a GLP-1 RA?

Because the emptying of the stomach takes longer for people on GLP-1 RAs, you’ll need to do a bit of extra preparation before your surgical procedure. Most people stop eating 6 hours before their procedure, and stop having clear liquids 2 hours before. If you’re on a GLP-1 RA, you’ll follow the same general pattern, but the timeline is longer.

The current guidelines recommend that you stop eating 24 hours before your procedure. At this point, you should switch to taking in only clear fluids. This includes liquids that you can easily see through, such as:

• Water
• Black coffee (no milk or cream added, although adding sugar is okay)
• Black, green, or herbal tea (similarly without milk or cream)
• Clear fruit juice (such as apple, grape, or cranberry juice) with no pulp or seeds
• Broth
• Sports drinks or sodas
• Gelatin (with no fruit or other substances added), which is the only semi-solid food permitted

In general, these substances pass quickly through your digestive tract, so they should be able to pass through your stomach before your procedure.

Starting 6 hours before your surgery, you should completely stop eating or drinking anything, including water. This will ensure that your stomach has time to completely empty before you go under anesthesia.

Safe and effective hand surgery while on a GLP-1 RA

Because the widespread use of these medications has only occurred relatively recently, the guidelines are still evolving, and recommendations may change in the future. This page is based on the most current guidelines from the Australian and New Zealand College of Anaesthetists. During your pre-operative appointment, we’ll share specific information about how you should prepare for surgery. Feel free to ask questions to ensure that you feel clear on exactly what you should do.

Always make sure to let your healthcare providers know that you’re taking a GLP-1 RA, because it can impact many different aspects of your medical care. It’s important for all of your doctors to be aware that you’re taking the medication, no matter who prescribed it.

Although GLP-1 RAs impact the process of preparation, it is considered safe to have surgery while you’re taking one. If you’re experiencing symptoms in your hand or wrist and would like to consult with an expert hand surgeon to see whether surgery might be a good option for you, please contact our front desk to make an appointment with Dr. Sungaran. With his extensive training and experience, he’ll be happy to let you know about all of your treatment options and advise you on whether surgery would likely be a good option for you.