HELP! Tandem Settings After Bariatric Surgery

Let me preface this with I know I need to speak to a doctor, but am in a weird scenario - my primary care and diabetes manager passed away. I was already on the path to bariatric surgery (modified duodenal switch), and I am 2 weeks from my surgery date. I am on the t:slim - she and I would have been working together to adjust my insulin dosing and monitoring, as well as thresholds to step down on treatment, but now I have a 6 mo waiting list for a new endocrinologist and a new primary care who acts as though she has never treated anyone for T2D.

I have sourced research on NIH and found evidence-supported guidance on reduction of fast-acting and long-acting (which we have to convert, obviously, for the pump). NIH study recommends cutting basal by 30% and bolus by 50% during pre-surgery low calorie intake. Post surgery is to discharge with 50% basal, and manually control bolus, with possibility that I may keep cutting by 50% at a time as I see what glucose ratings are.

I have Dexcom CGM, so I will never be in a situation where I can’t just decide to stop or change insulin levels if things are going awry. But the NIH recommendations are macro, not micro, and don’t get into things like correction factor or carb ratios, because they are assuming daily injections versus continuous pumping.

Any suggestions, experience, references or just plain advice on what to change? I can turn off control-IQ, I guess, and I can just change my personal profile to cut the basal rate by the recommendations, but I am not sure how/if/when to adjust the correction factors.

Will you be awake for surgery?

@Wenshop

I do not have any experience with bariatric surgery, but have a couple of general comments related to adapting to new condition:

  1. I would start by duplicating your existing t:slim profile and name it something like “Post surgery”. Then I would begin to “tinker” with the basal and other settings as you have described. I believe that the t:connect web app allows you to look at and print all of your profiles and, as I recall, does a pretty good job of tracking which changes were made when. In this way you can easily compare where you started and modifications you have made …

  2. I would also refresh your memory as to how to experimentally determine correction factors, in particular.

Finally, do you happen to live in California? There was a startup named Steady Health that provided online diabetes support. They were bought out by Carbon Health that offers both brick and mortar and online medical care. While I haven’t actually used either Steady Health or Carbon Health, the best CDE that I have ever had (who, in addition to being a CDE, is a RN, a T1D, a Dexcom user and a pump user) worked at Steady Health and now at Carbon Health. Even though they provide TeleHealth, I don’t think that they can provide interstate support because, I think, providers are only licensed on a per state basis. Of course, maybe there is a similar diabetes online support network in your state.

Best of luck.

John

It’s more complicated than simply adjusting your rates.
Bariatric surgery effects your absorption of all types of food including carbs. It’s impossible to know what your insulin needs will be afterward.
You will be eating far less and you will also be absorbing less of what you eat. As you lose weight your insulin resistance will begin to drop, reducing your need for insulin even more.

50% sounds about right because you don’t want to drop low and since it’s a shot in the dark, 50% seems like a decent starting point.

You will know pretty fast if you need more and then you can scale it up accordingly.

I know a type 2 who was taking 200 units per day!!! And she went off insulin completely within the first month after surgery. That means her old dose of 200 units would likely have killed her.

I don’t know what she was taking immediately after her surgery. She had intestinal bypass and stomach reduction, so it was a long time ago.
But really please be careful.