Thursday, November 21, 2013
I forgot how much picking a pump is like buying a car. You have these perceptions and this belief in what you'll get: sometimes it's better and sometimes it's worse. You never know until you drop into the driver's sear for a while. Fun fact that I learned: Medtronic Minimed (MM) has a 30 Day Return Policy. It's not advertised anywhere but they will tell you if you ask. If they really want to continue testing out their device, they will offer to extend that to 60 or 90 days. Honestly, I wish the 60 or 90 days was standard because how can you really know whether the system isn't for you or if you just need to become more comfortable with using it? More on how I knew for sure later.
After one week, I wrote this: "I've been waxing and waning between excited and apprehensive. So far, the Minimed 530g has me running Barenaked Ladies lyrics through my head, but the pump should be singing to me, including the the anger and frustration to the mutual apologies." I stopped there. I may have gotten a little stuck in the symbolism.
The first Enlite sensor I put in with the Minimed trainer was surprisingly comfortable. The insertion was easy-peasy. Loading the sensor into the insertion device was adult-insecurity-proof. Hold it flat against your stomach. In the sensor goes straight down at 90 degrees after on button press. Press and hold to pull the inserter off. So simple you could do it with one hand - I found that gimmicky. Seriously, when am I going to do this one handed especially considering the cost and lifetime of a single sensor. Using two hands is not the end of the world. Pulling the needle out and having it retract into it's personal housing was a spring-loaded cool and painless. Medtronic gets my props for designing that.
One of my old gripes about MM's previous CGM sensor was that the little seashell transmitter never stayed still. The eventually started selling seashell-shaped backing tape individual of the sensors but I hadn't stuck around long enough for that. The Enlite comes with backing automatically attached to the portion under the transmitter. That along with a special overtape (to go over the sensor but not over the transmitter unless you want a second piece) helped everything stay in place. Add one more short piece of tape to hold the seashell down and the sensor was pretty secure (wayyy more than the old one). The trainer told me that all the adhesive that MM selected was pressure sensitive so holding it down for 5 or 10 seconds would help the sensor stay on longer. Of the fours sensors I've worn, only one came off early and honestly that may be my own fault for getting caught on a door way (really, who's surprised).
I was happily surprised to see that charging the transmitter wasn't as big of a deal as I made it sound in the last post. Not eight hours. More like 30 minutes between each 6 days of wear. I only spaced on that once (with the sensor that came out early) where charging the transmitter slowed me down from running out the door, but I managed to keep myself busy with other things in the meanwhile. I imagine that taking a sensor out and putting the transmitter on the charger becomes second nature after you've been wearing it long enough so no reason to fuss.
After the initial sensor placement, there's a 2 hour warm-up period after which you put in a calibration (same as Dex). For a Dexcom, you actually need to put in two readings after the warm up and I usually do two immediately (aka I use the same value twice - shocking I know). For the Enlite, you need to enter another calibration within 6 hours. You should only put in one calibration in every 30 minutes. You must calibrate once every 12 hours or the Enlite sensor stops providing data. The way that the MM algorithm works is based on weighting the last four calibrations in order to translate from ISF to blood glucose. So if one of those calibrations is sub-optimal, then your accuracy is off until you get rid of the bad value in your log. None of this weighting nonsense exists with the Dexcom G4 system.
One of the big claims that I kept hearing over and over again is that you can calibrate the sensor whenever you want, with few exceptions. DEFINITELY a sales gimmick. For the previous MM sensor, you could only calibrate at times when your blood sugar is stable. I NEVER understood this. If I knew my blood sugar was stable, why would I be using your device? There are a ton of unreasonable assumptions: your blood sugar is stable when you wake up, when you go to bed, and before meals. Is it true for a lot of people? Sure. Does it work for me? No way. When I get up is the only real guaranteed stable point in 24 hours. After that, I'm running around like a madwoman, eating bits and pieces of healthy and unhealthy crumbs all day long, with nothing that resembles a schedule between two adjacent days. I'm in graduate school and everyone knows that college-life is not a steady well scheduled thing. I will eat ice cream before I go to bed. I will snack through my two-hour post prandials.
Different people will tell you different things. One rep told me it was okay to calibrate with one arrow. One told me never. A technical rep told me not to calibrate when I saw the sensor and meter values were far apart even when my blood sugar was stable at a high or low number. I could only calibrate when I was within a happy range. Another technical rep told me that I needed to get up and get my body moving to get my interstitial fluid (ISF) moving when that happened (to which I asked, I REALLY have to get our of bed in the middle of the night to stretch???). Coming from a Dexcom where you can ACTUALLY put in a blood sugar whenever you want, I couldn't handle this only calibrating during "stable" times especially since accurate calibration is what seriously affects sensor accuracy.
Another thing that is a little bizarre to me is the insistence that I use the Next Link Meter. Supposedly, this Bayer baby has better accuracy than other meters. I didn't notice a difference between it and my one touch mini the few times I did double fingerstick experiments. The 530g system was FDA approved with the meter, even though you can't bolus with it just transmit fingerstick values. No real complaints about the meter. The case is weird. The strips are a little harder to insert. I found myself looking down to see that the new strip hadn't registered even thought I had already splashed blood over. It is kind of nifty though that you can add blood afterwards if the sample is too small.
This accuracy issue goes right to the Low Glucose Suspend (LGS). I actually like how the LGS is designed and demonstrated. Basically, the pump turns off for 2 hours if your blood sugar is low. If you don't respond it basal insulin stays suspended and the alarm keeps hollering. There's a nice message on the display that says something along the lines of I'm a diabetic and I need help. Great for non-responsive situations. If you are responsive, you can chose to suspend the basal insulin for two hours to resume the basal activity. Let me say this again: I LOVE that this feature exists. I LOVE how simple it is to use. I LOVE the way it was designed. However, I cannot stand it when combined with bad sensor accuracy.
Every time (4 times total) I put in a new sensor I had the same problem: surprise LGS in the middle of the night when my blood sugar was fine. I verified that with finger sticks twice. I assumed the other two with good reason (::cough cough:: my Dexcom). The first time, the low alarms and LGS just kept me awake all night. The second time, the LGS went off and I slept through it, I never got the high alarm because the sensor was out of range, and I woke up high at 250ish. The third time, the LGS went off and and I slept through it, I got the high alarm as I woke up saying 186 mg/dl when my meter was saying 290ish. The fourth time, I kept getting low blood sugar and weak signal alarms, and I didn't get any sleep.
Accuracy when compared to my Dexcom was reasonable after 48 hours. Those first 48 hours ranged from atrocious to mildly irritating though. The Enlite sensor did much better on day six than day one. The Dexcom G4 sensors take about 12 to 18 hours before being a trustworthy accurate for me. However, their warm up period never quite reaches mildly irritating because I can always pop in a calibration ans see semi-immediate alterations in the blood glucose calculations. Also, an awkward comparison since the G4 sensors are good for seven days.
This brings me to my last few gripes. Sensor range. The range of a MM sensor should exceed my body. Getting a weak signal alarm when the sensor is in my left hand pocket of my jeans when my transmitter is on the right side of my stomach is asinine. There's no better way to say it. I shouldn't be getting weak signal alerts or lost sensor alerts when I'm in my bed. This is 2013. We can transmit things across countries. Bluetooth works at greater range. What kind of low grade tech are you putting into the transmitter that prevents this? Oh right, you didn't upgrade the transmitters. Just the sensors...
Alarm volume? Comparable to the Dexcom. However, I can amplify the Dexcom alarms in a low tech way (glass with coins next to my bed). I cannot sleep with my pump next to my head, because of the weak signal problems. My sheets and comforter muffled the alarms so much that I had no idea a LGS was going off til I peeled them down. Not cool. The vibration isn't all that strong either. I've had a whole lot of phantom pump alerts trying to keep an eye out for them.
Battery life? Well I guess you can say this was low because of the number of alarms. But really? 2 weeks before my first battery change is kind of sad, but I don't really know how to compare it since my Dexcom is only checking my sugar...
After the fourth sensor (and the 10th or so night of not sleeping), I decided to stick a fork in my diabetes tech experiment and ask for a return. You can't tell me I can calibrate whenever I want and then tell me I'm calibrating at inappropriate times. I also did not enjoy being treated like a child when I said it wasn't for me. I don't think medical devices should be a hard sell. My trainer put me on the verge of tears because they blamed my D-control was the problem when I blamed sensor accuracy and they almost had me believing it, which is super uncool with a condition that comes with as much of a mental burden as a physical one. I did break down on the phone with the continuing care representative a little bit. I all out bawled afterwards out of exhaustion, frustration, and high blood sugar. That said, all in all the customer service was much better than I was expecting. Lots of follow up. I know that they are people too. They get judged on who stays and who goes. I'm sure the everyone's under pressure with this new system.
So now, MM is processing the return. Two weeks minimum before everything is sorted out from the device end. No idea on how long refunding the insurance claim will take. I'm crossing my fingers that it won't be longer than mid-December so that I don't have to pay through the nose for a new pump and a new transmitter for my Dexcom because of deductibles (ironically the battery on that died this Sunday before I decided to return the MM system). What am I getting next? Still keeping my options open and doing way more research before I take the plunge again...
Ease of sensor insertion
Adhesion of the sensor
Low glucose suspend
Sensor accuracy (and therefore low glucose suspend)
My recommendation: Only use the system if you're comfortable with MM's CGM tech already. Otherwise Dexcom rules.
If there's anything I didn't discuss and you're curious about, leave me a comment!
Tuesday, October 29, 2013
Since I've been on an insulin pump for several years now, I have been lucky enough to see some of the diabetes technology devlop. All in all, I think (because my memory is too fuzzy to really remember) I've had at least 3 different Medtronic Minimed (MM) pumps. The latest and greatest 530g just came out as the successor to the Revel. I never got to experience the Revel first hand but one of the improved features was predicted alerts for the continuous glucose monitoring (CGM). I'm going straight from the MM Paradigm to the MM 530g, who's updated features included the linked CGM that allowed you to see your bloodsugar on the screen of your pump. If I'm wrong about this, I'm sure someone out in the DOC interwebs (because we're usually brighter than the average bears) will correct me. The funny thing about this whole experience is that while the Paradigm had the CGM ability, I only used it a handful of times before being so frustrated that I nearly pretended it never existed in the first place (which is saying quite a bit for someone who has the patience of an educator).
Regular readers will know that I've grown very attached to my Decom CGM that I lovingly call Eggy. I switched from MM to Dexcom two years ago because of that silly shell shaped transmitter. The transmitter would never stay put even with the assistance of every type of tape under the sun (that I could get my hands on at the time). The sensors were also crazy innacurate, and I could never get the calibration to work with my insane college schedule (really, who is stable for two hours when there are hormones and caffiene raging through you?). I held out for 4 months before deciding not to order another 3 month supply.
One of the other major things that bothered me was that the transmitter need to be recharged for EIGHT hours once a week. Add on the two hour calibration for every new sensor and replacing a sensor every three days. There goes 12 hours of glucose monitoring for your week.
In my mind, I expected that Minimed would change this as the technology improved, because this continuous monitoring thing was too new still. Or at least realize that they should send people two transmitters for the investment. That kind of logic is entirely false apparently. Even with a newer sensor that is FDA approved for SIX days of wear (the Enlite), you still lose eight hours of calibrating (ten if you add the two hours of calibration). This is all extremely perplexing when you add in the benefits of CGM plus low glucose suspend. If I chose those ten hours to be overnight while I'm sleeping, there goes the necessity of that feature. If I chose those ten hours to be during the day, I lose the ability to track my meal bolusing. I know that we're still miles away from "true" continuous monotoring but losing eight hours to charging the shell shaped transmitter seems asinine especially when compared to Dexcom system. All you lose is two hours a week for new sensor calibration if your efficent. Switching over has been a hard sell, my friends. But for aomeone who's struggling with perpetual hypoglycemia, I couldn't say no to a system with low glucose suspend and the timing for an upgrade just worked out.
I'm being adventurous and faithful to a company that has served me for over a decade. I'm also trying to keep an open mind. Maybe it won't be as bad as last time. My CGM training is tomorrow afternoon so hopefully I can throw in a new sensor before bed. I will try the dual Dexcom and Enlite for a little while since I've got the mother load of Dexcom sensors left...
If you have any specific questions about the system, let me know in the comments!
Friday, October 18, 2013
Two things I need to do: Basal testing and some light exercising.
And in all that extra free time I have: Postprandials to test my insulin to carb ratios and learning how to relax.