themighty logo

When I Had to Go 6 Days Without Auto Mode on My Insulin Pump


I’ve always been one of those patients who really beats on her pump. I mean really. Thankfully, it’s pretty dang durable. When I was young, I’d take it kayaking, ziplining, and rollerblading; constantly knocking it or dropping it, as kids do. In my days of college volleyball, my pump and I were regularly hitting the floor. Making “the play” was my number one priority and sometimes, I’d dive right on the pump. Oh well. Usually it hurt me more than it ever hurt the pump…and I had the bruises to prove it!

Medtronic Diabetes has always been amazing about pump replacements, overnighting me a new pump whenever necessary. Since I’ve gotten older, my life has calmed down a bit and I haven’t needed to replace my pump so much. In fact, I haven’t needed to replace it at all since I got on my Minimed670G two and a half years ago. A few weeks ago, however, I hit it just right and knocked off a crucial piece of plastic used to keep the reservoir in place. I knew I would need a new 670G.

I called Medtronic and they agreed to overnight me a new pump, but I was seriously dreading the switch. Talk about separation anxiety! If you’re on the Minimed 670G then you know that when initiating the pump, it is required that the user stay in manual mode for a minimum of 48 hours (three midnights) prior to switching to auto mode. Best practice, however is to stay in manual mode with CGM and suspend before low ON for six to seven days prior.  Why? Well… it has a lot to do with the auto mode algorithm.

Minimed 670G is currently the only (FDA approved) hybrid closed loop system on the market. When in manual mode, it works like many other pump/CGM pairings. Smartguard auto mode, however helps reduce glucose fluctuations by increasing and decreasing insulin according to the user’s sensor glucose readings. These micro-doses replace manual mode’s basal rates and are determined by the algorithm based on the previous two to six days of data, hence my six-day dilemma. Auto mode is conservative, but the more information that the algorithm has, the more aggressively it can safely deliver insulin. Factors that determine auto basal delivery include: current sensor glucose, how far it is from the target 120mg/dl, how long it has been away from the target, rate of change, and total bolus and basal insulin on board. Auto mode is clearly recognizable on the pump with a blue shield on the home screen. To me, this shield signifies protection from my highs and lows.

When I initially switched from my previous pump to the Minimed 670G, I was impatient. After the 48-hour minimum manual mode requirement, I immediately entered auto mode (despite my CDE’s suggestions). “Forget this,” I thought. “I’ve been in manual mode my whole life… I’m flipping into auto mode.” I immediately became frustrated with its conservative doses and it took a little longer for me to love it than it would’ve had I waited. I knew this time that if I could wait six days while wearing my sensor, my insulin delivery would be much more appropriately aggressive and I’d be happier overall.

It was a struggle, but I did it! Six whole days of manual mode! This experience made me realize (again) how much auto mode has decreased by diabetes burden. Trying to manage type 1 without auto mode help reminded me just how hard diabetes can be.  I’m glad I waited. It was worth it for the more safely aggressive delivery, but I’ve got to say nothing made me happier than seeing that blue shield again!