More on Tandem t:slim X2

Insulin Pump System with CGM Integration

If you’re looking for an insulin pump to add to your diabetes toolbox, it may be daunting to figure out which system best fits your needs and priorities. The key is identifying which system has the key features that meet your family’s needs, while minimizing your personal deal-breakers. We break it down for you here, with an overview of the  the t:slim X2™ insulin pump from Tandem™ Diabetes Care (with Dexcom CGM integration).

For a side-by-side comparison of Insulin Pump and CGM systems:
Comparing Insulin Pumps Available in Canada
Comparing CGM & Flash Systems Available in Canada

Key Features of the t:slim X2™

  • If you’re looking for an insulin pump system with integrated Continuous Glucose Monitor (CGM), the t:slim X2™ is designed to collaborate with Dexcom CGM (sold separately). What do we mean by “integrated”? The 2 parts – pump and CGM – work together within a single system: you can see your glucose data on the pump screen; the CGM communicates glucose data to the pump, pre-populating the bolus function so that you don’t have to manually enter your reading to correct a high. You also have the flexibility of using the t:slim as a stand-alone pump (without CGM) if you don’t use CGM, or if you use CGM part-time (like our family does).
  • If you’re looking for an insulin pump system that will reduce lows by shutting off basal insulin delivery when low glucose is predicted, then t:slim’s Basal-IQ™ fits the bill. Based on consecutive sensor glucose readings, if the system predicts that glucose levels will drop below 4.4 mmol/L within the next 30 minutes, it will temporarily suspend basal insulin delivery, restarting it automatically when glucose begins to rise. This can go a long way toward preventing lows!

(Be aware, however, that Control-IQ™ software currently available with t:slim in other countries, which reducing both lows and highs by adjusting basal insulin up or down according to sensor glucose values, is not yet available in Canada. A similar feature is currently available with the Medtronic 670G pump+CGM system.)

  • If reducing BG checks is a key priority, then note that its integration with Dexcom G6 makes the t:slim X2 the first and only CGM-enabled pump that is approved to let you make treatment decisions without pricking your finger AND no fingerstick calibrations are needed for the Dexcom G6.) This can mean virtually an end to fingerstick BG checks.
Wondering how accurate the different CGM systems are?
More on Dexcom CGM
Comparing CGM systems Available in Canada

  • Because of this move away from relying on fingerstick checks to confirm the CGM readings, t:slim is not paired with any particular blood glucose meter or manufacturer, you are free to choose any make and model for your BG meter. The downside of this freedom is that you can only bolus from the pump; t:slim does not offer a meter remote for bolus delivery from an external source. (So we’ll have to dig the pump out of our son’s Spibelt for middle-of-the-night blood glucose corrections.)
  • Large color touchscreen is intuitively designed and simple to use, eliminating much of the scrolling and button-presses required to operate a non-touchscreen pump.
  • Small size and sleek design. The t:slim X2 is the second smallest insulin pump on the market in Canada (slightly larger than the YpsoPump but much smaller than the Minimed 630G/670G or Omnipod PDM).
  • A rechargeable battery means you don’t need to buy replacement batteries anymore. This non-replaceable battery is medical-grade (leaps and bounds above the smartphone battery), lasts up to 7 days (5 days if using CGM) from a fully charged state to a totally discharged state, and has a 4-year minimum service life under normal use conditions.

Recharging can fit into your daily routine, since you do not need to disconnect, and you only need a 5-min daily re-charge. You can plug it in when you sit down for 5 minutes to check email, when you disconnect for a daily shower, or any other time that fits into your usual activities.

Rechargeable batteries are, however, a double-edged sword. Carrying around a backup-up lithium battery in your d-kit doesn’t provide an emergency backup (like we’ve needed more than once in the past!) If you don’t routinely charge it, you may need to find a plug-in on the fly.

  • In terms of rates and ratios the t:slim X2 has:
    • the smallest basal rate increment of any pump currently available in Canada (though the smallest minimum basal rate belongs to the Medtronic 630G and 670G insulin pumps). This means that you can increase or decrease the basal rate by steps as small as 0.001 units/hr, a step ten times smaller than the pump with the next smallest basal increment. For example, if a basal rate of 1.0 units/hr is not quite strong enough, you could try a basal rate of 1.001 units /hr; with another pump you would have to move up to 1.01 units/hr. This flexibility may be important for small children or anyone who is highly insulin sensitive.
    • the smallest bolus increment at 0.01 units (though the smallest minimum bolus dose belongs to the Medtronic 630G and 670G insulin pumps). This means that if 2.0 units is not quite enough, you can delivery a bolus 1.01U, or 1.02U, or 1.03U, etc. This is less than half the size of the bolus step possible in the pump with the next smallest bolus increment. This is an important feature for small children or anyone who is highly insulin sensitive.
    • the longest duration for a temporary basal function (72 hours = 3 days… we had to re-set our son’s temp basal every 24 hours on his Animas pump) with the largest range (up to 250% of your programmed basal rate).
    • the largest maximum Insulin-to-Carb ratio (I:C) at 1:300, as well as the largest number of time segments (16) in which you can set a different carb ratio across the day.
    • the largest possible Insulin Sensitivity Factor (ISF) at 1:33.3 as well as the largest number of time segments (16) in which you can set a different ISF across the day.
  • Pump updates are simply a software update. If new features come out, you don’t need to wait 4 years to get a new pump, you just connect the pump to your computer using a universal USB, and (after meeting the qualification criteria) you download the software update to your existing pump.
  • The trade-off for this updateability (and open USB port that makes it possible) is that the pump is not waterproof like most other insulin pumps on the market. The t:slim X2 has a watertight IPX7 rating (water-resistant to 1 meter (3 feet) of water for 30 minutes, but it’s recommended that you don’t swim, surf or bathe with it. If swimming with your pump is an important part of your family’s lifestyle, then this may be an important consideration for you.
  • Tandem employs a full-time psychologist who studies the intersection between diabetes and technology, working with Tandem’s engineers to design a pump that meets makes life with diabetes a little easier. As one example, when glucose is above-target, the Combo Bolus function delivers the glucose correction up front; you don’t have to manually separate it out for a separate bolus and then go back in the combo the food portion of the bolus (like our family has to do with my son’s current Animas pump). Another example: there’s a “T button” that functions as a one-press Back to Start, for when you want a quick exit from the menus. Also, to make programming of the Personal Profiles easier, you can copy an entire existing time segment and then change certain parts of it; you don’t have to create every new personal profile from scratch. Seemingly small time- and hassle-saving features add up to a big reduction in stress when you’re living with diabetes.
  • The t:slim offers useful alerts to help users follow through on diabetes best practices, including:
    • Incomplete Bolus Alert lets you know if you started a bolus request but did not complete the request within 90 seconds. The alert repeats (with audible tone, or vibration, according to your settings) every 5 mins until acknowledged. (This alone would eliminate MOST of my son’s missed boluses!)
    • High BG Alert that prompts you to give a correction bolus if the CGM says your glucose is above-range AND there is no active insulin remaining.
    • Low BG Reminder that prompts the user to retest blood glucose after a Low BG has been entered.
    • Missed Meal Bolus Reminder which prompts the user if a bolus has not occurred during the period of time the reminder is set for.
    • After Bolus Reminder prompts the user to check BG at a selected time period (between 1 to 3 hours) after a bolus has been delivered.
    • Low Insulin Alert gives you a heads up if there is 5 units or less of insulin remaining in the cartridge.
  • You’re no longer limited to switching between Alternate BASAL profiles to match your insulin needs on different days and under different circumstances (workout days, sick days, menstruation, weekend vs weekday, more conservative rates for sleepovers away from home, sedentary travel days spent sitting in a car for family road trips). With the t:slim you can create up to 6 separate Insulin Delivery Profiles to individualize your insulin doses in terms of:
    • Basal Rate (your basal rate in units/ hr)
    • Correction Factor (amount 1 unit of insulin lowers BG)
    • Carb Ratio (grams of carbs covered by 1 unit of insulin)
    • Target BG (your ideal BG level, measured in mmol/L).
  • The cartridge is designed a little differently than pumps from other manufacturers. It uses pressure to draw the insulin up into the tubing and on to the infusion set (rather than using a piston to push the insulin up). This is both a safety feature and a design choice that allows for smaller, slimmer pump dimensions. As a result, the cartridge fill works a little differently than with other pumps, which may take some getting used to.
  • If peace of mind in terms of pump failures and same-day replacement is a deal-breaker for your family, then you may want to note that currently pumps and supplies are not distributed in Canada directly by Tandem, but are outsourced to a third party, Diabetes Express. This means that t:slim pumpers are subject to the third party operational practices, including open hours: if your pump goes down, the quickest you’ll get a replacement pump is the next business day; if you’re unfortunate enough for you pump to go down on the Saturday of a long weekend at 1:30p (after their 1:00p closing time), you’ll be waiting until Tuesday for a replacement. Without another back-up pump in place, this may mean a temporary return to injections.
  • If you like “in house” d-supplies, you should know that Tandem makes and manufactures their own cartridges.

We hope the above information helps you to choose an insulin pump, for yourself or for your child, that best fits your unique needs and preferences… all the best with your pump shopping!

This material has been developed from sources that we believe are accurate, however, as the field of medicine (in particular as it applies to diabetes) is rapidly evolving, the information should not be relied upon, as it is designed for informational purposes only. It should not be used in place of medical advice, instruction and/or treatment. If you have specific questions, please consult your doctor or appropriate health care professional.

Share this Article