Saturday, April 14, 2012

Insulin Before Surgery: Don’t Change the Lantus

It is shocking how many doctors and patients don't know what to do with insulin before surgery. Perhaps because there are no universally agreed upon guidelines. 
The Society for Ambulatory Anesthesia came up with some reasonable ones recently.

Mut maybe because of that lack of consensus, often anesthesiologists or surgeons tell patients to stop or reduce their Lantus insulin. Lantus and another insulin called Levemir are typically given in the evening. These insulins have no significant peak. That means they work fairly smoothly and evenly over many hours such that they do not tend to cause low sugars even without eating.

Now that statement is true if the patient is taking an appropriate amount of Lantus. Unfortunately, too often doctors, even some endocrinologists, prescribe huge doses of Lantus insulin, without also prescribing another type of insulin needed to control glucose rises from meals. An excessive dose of Lantus may require the person to eat to avoid getting hypoglycemia  (low blood sugar). Many doctors would benefit their patients by reading my previous post on how to use insulin.

In general, though, the long acting insulin, like Lantus can and should be given as usual in almost all patients before surgery. Some patients take Lantus in the morning. They too should take their insulin as usual even on the day of the surgery.

If the person has Type 1 Diabetes, reducing or stopping the Lantus can lead to severe hyperglycemia (high blood sugar) and serious, even life threatening problems. 
Diabetic ketoacidosis can quickly result in a person with Type 1 Diabetes who skips insulin. It would indeed be unfortunate if ketoacidosis happened because a doctor told that person to stop their Lantus.

I’ve seen it happen more than once.

That’s why our team always tells patients to call us for insulin instructions before surgery and not to listen to what others tell them.

These problems are completely avoidable.

Here’s hoping that surgery, if you need it, goes well.


  1. Not exactly related to this blog but a question about insulin- should I take any insulin during a marathon? I have not used my pump during the long runs. I have only experienced a drop in blood sugar during runs (I take carbs during runs). My long runs haven't been longer than 3+ hours. My marathon goal is 3:45. I am a 63 year old type 1 diabetic. Provided I qualify, I'm planning a 50 mile trail race and I have the same question- do I take some amount of insulin during the event? My pump will deliver as low as .05 units per hour. Any advice is appreciated.

  2. In general, some insulin, a very low basal rate is necessary to avoid ketoacidosis and help you use the carbs. You can learn as to what works for you, speak to your endocrinologist and check out the online community of
    the diabetes and exercise group, most of whom have Type 1.
    And congratulations on your hard work. Good luck on qualifying!

  3. I'm probably going to cut my usual basal rate for that time of the day which is .35 units by 80% which will give me .07 units per hour during the marathon. I've read a few blogs and asked members of diabetics who run marathons at and I've read The Diabetic Athlete by Sheri Colberg who recommends cutting the basal rate by 25 to 100% during the marathon. I will take carbs with me and use a cgm setting the alarm so it notifies when I'm below 120. Please let me know if I'm on the right track.

  4. Sounds very reasonable. Good luck and discuss this plan with your endocrinologist.Make sure you have a high alert set also, probably around 200 or so.