Scary 4am Low: A Cautionary Tale

I’m a little rattled this morning by the events that played out last night when I should have been sleeping peacefully.  I’ll do my best to convey them here now:

I went to a holiday party last night and both drank and a ate a bit closer to bed time than I like to; it seems the food in my stomach when I’m sleeping digests a bit quicker and I tend to spike a bit higher than I might if I didn’t go to sleep so soon after eating.  I also walked home from the party and was seeing double down arrows on Dex and a BG of 175 which from experience I knew would either level off at 175 once I stopped walking/went to bed, or would continue to raise one I went to bed and super-digestion commenced.

So, I went to bed last night expecting a bit of a BG-coaster but after a comedy of errors, what I got was so much worse.

Here’s what I remember:

Around 4am, I hear M asking me if he should get me some orange juice. I must have been feeling the low at that point because M usually responds only to my squirming and not to the sound of Dex. I also must have been pretty low because when he asked, rather than saying “no” like I normally would do and getting the juice myself, I said “please” and I put my head on the pillow and let the cold sweat drip over my skin.

He brought back a full, tall glass of orange juice (at lease 4x what I would normally use to treat a low) which I drank in two gulps.  He got a second glass that went down just as easily.  I lay there for a couple minutes to try and let the juice absorb when I decided to actually look at Dex.  58 mg/dL.  Not too bad. But 58 wasn’t really a good description of how I felt. I felt sub-zero. So I grabbed my meter and checked.  32.  That’s more like it.

I went into the kitchen and ate a few spoonfuls of pistachio Haagen-Dazs and Nutella.  M came to check that I was ok and laugh and my standing in front of the open freezer with a carton of ice cream and a spoonful of chocolate.  I went back to bed and back to sleep.

In the morning, I assumed I would be sky high but Dex was only reading in the 120’s.  A check with my meter confirmed it.

7 am BG after overnight low.

7 am BG after overnight low.

WTF? Where’s my sky high BG that should have followed my massive 4am consumption?  Looking at Dex confused me even more – this low occurred after a rapid drop in BG at 2am.  I must have awaken to the sound of Dex alerting me to a high and I must have groggily corrected my BG of 185 (as determined by Dex) and corrected with a bolus from my shiny new t:slim pump.  (Now, I know I shouldn’t be correcting from my Dexcom, but I do. And I’ve found it to be reliable enough and even when it’s not the outcome is generally not so far off to be a problem. Generally.) This is the sort of overnight correction I am in the habit of doing, and doing it is barely a blip on my radar and happens mostly on autopilot.  So, I decided to check my pump history to see if this was the case.

t:slim history screen showing a surprise.

t:slim history screen showing a surprise.

Looking at the above image, I was shocked.  I initiated a 15 u bolus at 2:24 in the morning.  Why?  Purely by accident apparently.  The t:slim displays 3 things for every bolus: the time at which it was completed (boluses can be a bit slow, in this case at 2:48 am), the time it began (2:42 am) and what was entered to initiate the bolus.  See in the picture it says “B: Food/BG” then “183 g/NA”?  This means I bolused at 2:42 am for 183 g of carbs rather than a BG of 183 mg/dL!  What should have been 2 u was 15 (max bolus allowed by my pump settings).

How can I make such a stupid mistake? I’ve only been using the t:slim for about a week and I love so many things about it, including that I no longer have to dial in  the units for a bolus.  However, dialing in that number has always provided me with a check that I couldn’t ignore before delivering a dose of insulin. The t:slim asks me 3 times before delivering a dose; it does a good job of shoving information in my face.  What it doesn’t to is engage my brain enough during autopilot to help me see the error of my ways.

This is what you see when you initiate a bolus with the t:slim

This is what you see when you initiate a bolus with the t:slim

The bolus screen clearly indicates where to enter a BG and where to enter carbs.  However, once you click, the next screen is nearly identical for each:

BG or carb keypad

BG in carb windowBG in BG window Keypad; BG in carb window; BG in BG window

Once the numbers are entered, it displays a calculated dose then you hit “next”, confirm twice, and done.  The bolus initiates and the pump vibrates quickly upon completion.   With auto-pilot initiated, I entered and confirmed and was asleep long before the vibration.  End of story.

So.  What have I learned?

  1. The obnoxious dial-a-bolus method used in all other pumps may have irked me most day,s but it did provide me with a mental check that probably would have prevented this from happening.
  2. Actually using my meter to confirm my Dex BG would probably have taken my brain far enough out of autopilot to notice my mistake and prevent this from happening.
  3. For some reason, my first instinct when I go to calculate a bolus is to click on the left most box first, and when my brain is in BG mode instead of carb mode, there is potentially a problem.

I started with the t:slim about a week ago.  While I am still smitten by it, I’m realizing I need to approach this change with a bit more caution that I have been.  I’ve had Animas’ pumps for about 12 years and I can use one with my eyes closed.  I’m going to have to spend some time focusing more on D and destroy my old auto pilot (or at least reprogram it).


t:slim touch screen

I mentioned in my first impressions of the t:slim that I was underwhelmed by the responsiveness of the touch screen. However, I want to add that I am thoroughly impressed that I can operate the pump while wearing gloves. And not those special conductive gloves you need to use your iPhone, but regular gloves that render my iPhone useless.

I’ve been attributing this (both traits actually) to there being a different touch mechanism in play with the pump verses the iphone.  An iPhone is a multi touch system that uses a capacitive material to sense touch.  This material is only activated by conductive materials (like your finger or a conductive glove) and most gloves (ie insulation) stop those signals from transmitting.

The t:slim seems to sense touch via pressure via a resistive screen. This means that it only registers a single touch at a time (which is all we need to operate a pump) and can be activated by anything capable of delivering pressure, be it conductive or insulating, thus there is no need for conductive gloves.

I haven’t taken the time to seek out Tandem’s patents or specs to know if I’m right (maybe someone else has this info?) so I certainly could be wrong.  I’m just glad that I won’t have to purchase special gloves (!).

I hate needing special equipment to use my special equipment!

More info on how touch screens work, etc:

T:slim – first impressions

It’s Thanksgiving and today I’m thankful for life-sustaining medical technology that’s also nice to look at and easy to use. My new touch screen pancreas t:slim insulin pump arrived on Tuesday and after 24 hours of patience, I ran out. So I opened the box, unwrapped my new toy durable medical equipment and began my d-life again without the hassle of dialing in carbs and BG values. It’s been a measly 18 hours since I first plugged her in (name pending) but I’ve already identified a few pros and cons about the newest member if my diabetes team. Since today’s a holiday I’m leaving this post in bullets but I assure you I’ll do my best to update this post as my experience with the t:slim evolves.

• Touch screen!!! Hello 21st century.
• Back button and Home button
• Bolus calculator – as in “I had 10+6+32+1+7g of carbs, bolus please!”
• Pretty, shines, modern, relatively small
• Copy/paste basal program – build a new basal program without having to start from scratch.
• Basal program includes ISF, I:C, and target BG
• I:C can be entered in half grams
• IOB on home screen
• 75 xtra units – see cons for explanation.
• Great history menu includes entered BGs, blouses split by type and if the calculated dose was overridden.

Cons Less awesome things:
• Touch screen less responsive than I expected
• 9 button key pad, as in three letters per button. But you only need this for naming basal programs so who really cares?
• Very slow priming and insulin delivery. Ugh!
• Only corrects for low blood sugars under 60 so I need to be a bit more conscious when dosing food with lower BGs
• Clip is a bit poorly placed on the case – only slightly north of center so the pump hangs forward while clipped to my pocket.
• Leur lock connector in awkward position and I can’t seem to hide it.
• Uses close to 50u to ready cartridge and prime 23in tube ( as opposed to about 25 for the ping) so the xtra 100 units I fill are really only and extra 75.

• Wall charger – I was directly connected to the grid for about 10 min this morning
• Multiple confirmation screens before bolus initiates.

And that’s all I got for now.

Switching to the t:slim’s been nearly 9 months since I last posted anything on this blog.  Either this post will the turning over of a new leaf or maybe I’ll neglect the blog for another 9 months.  Only time will tell.

Until then, I’m here to tell the world that I’m making the change over to Tandem and should receive my new t:slim within a couple weeks.  I’ve been using an Aimas pump for nearly 12 years.  I stated on their IR1000 model (a brick with a cord), switched to the IR1250 (for the carbsmart calculator and the free iPod mini that came with it), then my beloved Ping.  As far as I’ve always been concerned, no other brand was even worth looking at – Animas is and always has been fully water proof (I’ve worn it under waterfalls, and in lakes and pools), has easy (enough) to navigate menus, and great customer service. (Although it was better back in the day when everyone else was on minimed and I was Animas’ only customer.  Not really, but that’s how it often seemed.)  I remember fighting my doctor to subscribe Animas over minimed.  I knew it was the pump for me and I couldn’t be convinced otherwise.  And to this day I have always had great experiences with my Animas pumps.

Then one day there was Tandem.  The t:slim is smaller, holds more insulin, is rechargeable (no more expensive lithium batteries insurance would never pay for), has a touch screen which allows carbs and BGs and boluses to be typed in instead of dialed, and the ever ellusive back button.  I was instantly twitterpated; it’s like Tandem knew all the things I wanted out of a pump and poof there it was!

Yet I remained reluctant.   Tandem does not offer pump trials; the t:slim is not water proof (merely water resistant); and perhaps most importantly is a start up company just breaking into the market with a first generation product.

And then my Ping’s warranty expired.   Do I sign up for 4 more years of Animas or do I take a risk and give this new company a try?  They have a 30 day return policy (from start-up day) and the only way they make to the next generation is by having customers willing to give them a chance.  Plus they’re teamed up with both Dexcom (integration, please!) and the dual-chamber-bihormonal-closed-loop-pump people at Mass General so they have a bright looking future.

I got word of my approval today and I’m pumped (excuse the pun).  Let’s hope it’s worth the gamble.