Eli5: What is the purpose of sugary drinks after coming out of anesthesia?

Question

I’ve had to go through quite a few medical procedures under anesthesia. I’ve been told by nurses that my having red hair, freckles, pale skin, and green eyes makes things a bit more complicated than other patients concerning anesthesia. I don’t know if this factors into the sugary drinks or not. I’m always offered a selection of juice when I wake up. I’ve also got a diabetic friend who uses juice for when their blood sugar gets low. Which made me wonder, since you have to fast before anesthesia, does the juice/soda have anything to do with blood sugar levels post procedure?

In: Biology

Answer 1

Many hospitals will tell you to hydrate with clear liquids—like clear Gatorade/Powerade, simple juices, or plain water—up until 2 hours prior to your surgery (or up until midnight before surgery, which is a bit of an outdated practice). This mainly allows you to stay hydrated (which keeps your blood pressure, heart rate, and other vitals a bit more stable during surgery) and may provide your body with an additional source of easily available energy when the drink contains some sugar.

This practice has been shown to improve patient satisfaction, reduce postoperative nausea, and accelerate discharge after surgery, so it’s now common for hospitals and surgery centers to do this routinely. In the anesthesia world, it’s often part of a set of guidelines called an Enhanced Recovery After Surgery (ERAS) protocol. After surgery, you may get some juice to maintain normal blood sugar and to ensure that you can hydrate by mouth (rather than getting fluids through an IV), though this isn’t required for most patients to be sent home after day surgery.

By the way, a red-haired/freckled complexion is associated with a particular mutation in a gene that codes for the melanocortin-1 receptor (MC1R). The presence of this mutation tends to cause patients to require higher doses of certain anesthetic drugs to keep them asleep and comfortable. It doesn’t *necessarily* complicate your anesthetic, but it does sometimes mean that you’ll need more medication.