Leaking POD

Type 1 and LADA Parents of Children with Type 1 Diabetes
1

So, let me give the background. We had taken off Liam’s POD around 2200 because it received an error (which is OK because it was due to expire at 2330 anyway. So, because we usually turn off his POD basal rates at night anyway due to him dropping low, we decided to just see if we could wait till the morning to put on the new POD, before breakfast. He was around 125 at bedtime so we gave him a small 5 carb snack because we need to have him above 150 usually for him to make it through the night without dipping low (he always gradually decreases (very slowly, over hours) during the night.)

Well, around midnight, his BG was getting up around 250…which I wasn’t comfortable with him sleeping with the BG that high. He would have stayed over 200 for 1/2 of the night or more before dipping under 180. So, I decided to put on a new POD while he slept. The process was just like any other time and he didn’t even wake up.

Because he was near 250, the PDM recommended a .25 correction…knowing this would take him under the range we are comfortable with for him, while he sleeps, I only gave him .10 (which should have brought him down to between 180 - 150. Keep in mind that the basal was turned off so all he had in his system throughout the entire night was the .10 correction given to him around 0030.

However, from the image below, you can see what happened throughout the night. Around 0500 the low alarm sounded. I checked and it was 47. I quickly gave him 1/2 box juice. Then at around 0600 he was up to around 150 (yay!) So I am sleeping again, then around 0800 the low alarm goes off again! I check him and he’s 50! So I give him the other 1/2 of the box of juice. Then around 0900 he crests only about 100 before beginning to dip again! So I say the hell with this and just give him an entire box of juice. You can see that this took him to around 225 at 1000 or so. But…then he nose dives back down to 50 again!

So, although we had just installed the new POD, I felt like somehow insulin was leaking into his system in large enough amounts to make him crash quickly so I have taken off the POD. He’s now around 120 and we are waiting until he’s “level” for 30 minutes or an hour or so before feeding him any carbs.

Has anyone had a drastic of an issue as we just had last night as far as…what I have to believe is a leaking POD??

Yes, the liver secretes glucose. Yes, he dips low and it’s normal for that to occur during the night, but NO, it’s NEVER so drastic of cliff dropoff’s in BG rates! It should only a 5 or 10% gradual decline over the night per hour…not a 100% decline in 2 hours!

Anyone with any additional info or anyone that can confirm my theory it would be great. Last night was horrible! As you can see 4 Hypo’s last night / this morning.

2

Sorry, just a dumb question since I don’t know everyone’s story yet.

How long has Liam been a diabetic? I know that for T1D’s that are very early in their diagnosis, their body can still make insulin. - The Honeymoon Phase amongst people with type 1 diabetes refers to the period of time shortly following diabetes diagnosis when the pancreas is still able to produce a significant enough amount of insulin to reduce insulin needs and aid blood glucose control.

If you have ruled that out, I suppose it is possible to have a leaking pod, but it is very unlikely that it would leak into his body. If you think of holding a straw with fluid in it, and your finger over one end of the straw, the fluid won’t come out the OPEN end. It’s like that with the reservoir in the pod. Possible, but unlikely I think.

I think a more likely possibility is that the insulin that was already in his body, that had been previously delivered, was delayed. So you had the insulin delivered before, and then the correction, and those hit at the same time.

My experience with insulin absorption has occasionally been scary. One time my BG dropped (I mean a huge plummet) about 6 hours after my last bolus.

I would suggest looking through the pod delivery history, make note of all the bolus numbers for that night, and see if you had a delayed absorption.

In my opinion (and I am just going by instinct), the problem was either honeymoon or delayed absorption.

Hopefully I expressed these things clearly.

EDIT - After looking at that picture again, I think Honeymoon seems a more likely explanation. But save that pod, I think Insulet might want to take a look at it.

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3

While I do think it’s possible for any technology to fail, my long experience with many brands of pumps, I’ve never had an uncommanded insulin over-delivery event that was not explained by some user error. It think it’s possible but highly unlikely.

One thing I’ve found is that blood sugar trends have a tendency to repeat if all other inputs are held steady. In other words a yo-yoing BG wants to continue to yo-yo and a low-variability trend line wants to maintain its low variability. I think of it like BG momentum.

This is a puzzling event, especially since you were so conservative with post-pod start-up correction of 0.1 unit. It’s worth the effort to try to understand what happened in situations like this because you can learn from them. But if it takes longer than 10 or 15 minutes to draw some confident conclusions, it’s probably just time to move on.

You’re dealing with a growing child and it’s not just insulin and glucose in the mix here. Your toddler likely has regular occurrences of growth hormone secretions. I’ll be curious to read if any one else might have some insight.

4

This is true; however, since he’s been diagnosed this past February he has always had to have his insulin turned off during the nights to avoid dipping low “by the end of the night”. If we kept .05/hr basal on, he can typically still be fine until around 0500 - 0600. And the .05/hr would cause only a slightly more dramatic decline of 10 - 15% / hr instead of what we see in this image. What I see here is three very severe drop-offs that are unexplainable to me (in the absence of insulin). Usually, without Insulin…if we give him a 1/2 juice box that would have been more than sufficient to take him back up and hold him there for the remainder of the night. Requiring 2 juice boxes in a single night is more than growth hormone. There were severe and sharp bg drops occurring all night. If growth hormone CAN cause this, then OK…maybe that’s what we have here…but I’ve never experienced something so dramatic in a single night. In my mind there should be no “Yo-Yo effect” because he was not getting insulin…as a T1 toddler, who was not exercising and had no insulin (and isn’t sick) his BG after that first 1/2 juice box should have gone up and stayed up until something (exercise or insulin) brought it back down…or his normal body secretions brought it down “gradually”.

I don’t want to believe that the pod leaked, but I have a hard time discounting this as merely growth hormone secretions?

5

He was diagnosed Feb 29th, 2016.

There may be a slight chance he is still in honeymoon, but we haven’t ever seen this dramatic of drop-offs in BG’s, multiple times in a single night, without insulin in his system. This is the first time since he was diagnosed that this has happened.

This is assuming the straw (cannula) doesn’t have a hole/leak in it. If it did, it would/could leak out?

Prior to the correction at 0030, he didn’t have basal since 2200 (2.5 hours had passed since his last basal). And prior to that, his last bolus was at around 1900 for dinner. In my mind at least, since I didn’t do an “extended bolus” for his meal at 1900, the “effects” of that bolus should have (if history holds true for his body) been out of his system by 2200 tops. 3 hours is how long insulin takes to do it’s full work (go up and back down to pre-bolus BG levels). If the insulin I delivered at 1900 was delayed, that’s another concern I suppose since I didn’t select any extended bolus, so it should have all been in his system at time of delivery and done it’s job…(which you can see it did because when I removed his POD at 2200 before giving him a nighttime snack, he was 125…(which was his “pre-bg”).

This may definitely be a factor for the first dip…but the 2nd and 3rd?? There would have been zero insulin in his body…really even before that first major dip…but the 2nd and 3rd ones also? We are talking about 10 - 12 hours passing with only that one .10 insulin dose given at 0030 at night! That’s a lot of time, (and a lot of damage) for a .10 insulin shot to do to his body…4 times!

6

Are you diluting the insulin? If not, I’d like to discuss that. There are TREMENDOUS benefits to that. So many benefits in your situation.

8

Around 5:00 a.m. Liam experienced a significant low that pegged the Dex to 39 mg/dL and you measured 47 mg/dL. It looks like it was about a 30-minute low. I’ve found that when that happens, my body releases some potent counter-regulatory hormones that play havoc with maintaining good control. In fact, I am surprised that he didn’t continue high after that but instead plummeted again.

I think this is complicated to analyze and draw a confident conclusion. Your basic inclination to figure it out is healthy but I’m not sure you can positively discover what happened. I still think it’s highly unlikely that your Pod over-delivered and the answer may lie in the dynamics and kinetics of the absorption site.

9

We are not because we have never had the need to do so. The insulin (Novolog) has always done the job it’s supposed to do when we dose like we should dose. I have read about diluting and understand the process…it’s just not something we’ve needed to do because, besides this isolated incident, we’ve never had issues that couldn’t be explained away as just human error.

Neither my wife nor I can explain this isolated event, but other than this event, we’re getting a firm handle on his insulin/Diabetes management and have come a long way in our understanding since February.

10

I was just thinking that with dilution you can have much more granularity in basal rates and boluses.

Since the OmniPod’s smallest increment is 0.05, that’s a pretty big amount for a little one. If you diluted 50%, you’d have the ability to do 0.025 increments. That gives you much more control over bolus and basal amounts. And any errors in delivery by the pod are also cut in half.

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11

Maybe along with the carbs you’re using to treat low add some protein (peanut butter) to help maintain his bs. Granted I’m not a toddler, but I see the same thing when only treating with carbs. I’ll get the quick bounce out of low range with the carbs, but then will gradually drift back to low without any protein.

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12

The mechanical design of the pumping mechanism simply makes it impossible for any insulin to leak in any way, or be delivered through the cannula without the pump mechanism “pumping”.

The insulin reservoir has a plunger at one end that is gradually pressed through the cavity by a fine-pitch screw. This screw is turned by a ratchet. The ratchet is advanced one gear tooth by an SMA wire that contracts when energized. Each “click” of the ratchet moves the plunger in the reservoir exactly 0.05U worth of volume, pushing the insulin through the internal tubing and out the cannula.

So, unless you hear the pod clicking (when delivering a bolus, about 1 click every 1.5 seconds), it’s not delivering any insulin.

Since Liam was diagnosed only back in February, I suspect strongly he still has beta cell function, and this accounts for the mysterious drops in BG. It also would account for quite a bit of the variability and uncertainty you’ve been fighting in trying to control his BG and avoid lows. You’re not the only one giving him insulin.

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13

This is excellent advice, and given the situation, I’d probably dilute 4:1 or so.

14

I haven’t ever “heard” insulin being delivered. I hear it priming and I
hear it going into his skin. Those are the only sounds I ever hear. Good to
know how it works though. Thx

15

[quote=“ClaudandDaye, post:14, topic:57934, full:true”]
I haven’t ever “heard” insulin being delivered. I hear it priming and Ihear it going into his skin. Those are the only sounds I ever hear. [/quote]
Next time you do a bolus, put your ear up to the pod and listen. For every 0.05 units of insulin you are giving, you hear one “click”.

I listen for that all the time, because since you can’t see it, it’s comforting to know that insulin is being delivered.

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16

Thanks for the great explanation. I think many people think the basal insulin delivery is ‘continuous’, meaning a small increment every 1-5 minutes, or truely a ‘continuous’ turn of that screw/plunger. But it is based on the pump and how much is delivered with each ‘click’. I believe the latest MM pumps can do .025 per click. (I thought one of the pumps, maybe Snap, actually was ‘continuous’ and click-less).

For MM pumps, and different infusion sets, the ‘prime’ amount is variable and determined by the user. With omnipod, is it user set, or pre-programmed, since all pods have same cannula ?
I wonder if in this case, the cannula fill pushed out a small amount that ended up being absorbed, causing the unexpected IOB. For most adults, an extra .05 at pod change probably would not even make a noticeable difference. But in Liam’s case, might appear as a ‘leaky’ pod. Best solution would be to do pod changes when bolus is about to be done, to reduce impact. Maybe a call to Omnipod would help.

17

The honeymoon is a double-edged sword. Nice to still have some endogenous insulin happening. But the release of endogenous insulin is extremely variable and exceptionally unpredictable. If I were forced to put money on why you rode the glucocoaster, I’d say that was the reason. Which is why you shouldn’t spend another moment trying to figure it out. Just correct, move on, and keep doing the great job you’ve been doing.

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18

I just hate, if it’s truly the honeymoon phase, that I changed out the POD. :frowning: I hate putting him through these…

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19

I hear you loud and clear, Harold. My daughter does about 75% of her own Pod changes. Even though I never see her so much as flinch, the sound of the cannula deploying drives a tiny dagger into my heart every time. Hang in there, buddy! :heart:

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20

[quote=“MM1, post:16, topic:57934”]
With omnipod, is it user set, or pre-programmed, since all pods have same cannula ?I wonder if in this case, the cannula fill pushed out a small amount that ended up being absorbed, causing the unexpected IOB. [/quote]

For OmniPod, the application process has it prime before you put it on your skin. In theory you could put it on your skin before priming, but that wouldn’t be following the correct procedure. Insulet would just tell you to do it the right way.

For the frequency of basal delivery (in minutes), OmniPod’s formula is this:
60 / (hourly basal amount / 0.05 )

For example, if your basal rate is 0.50 units per hour, it would deliver 0.05 units every 6 minutes. 60 / (0.5 / 0.05) = 6 minutes

EDIT: Actually, even if you stuck it to your skin, the cannula isn’t deployed yet, so the priming wouldn’t push anything into your body. Sorry, I wasn’t thinking through it all the way.

21

And it’s anyone’s guess what “it” truly was, and the uncertainty isn’t due to any lack of knowledge or diligence on your part. So please stop beating yourself up. (That’s your wife’s job!:wink:)

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