• Guest - w'd love to know what you think about the forum! Take the 2026 Survey »

Steel cannulas for T:Slim

RobertJ

RobertJ

Well-Known Member
Messages
269
Location
Cambridgeshire, United Kingdom
Type of diabetes
Type 1
Treatment type
Pump
I have had the Tandem T:Slim X2 since June 2023. Over the last 6-12 months, my control has got worse. More and more often, I've had what I term 'mystery highs' where it goes really high after a meal and I have to change my set earlier than the three-day period. My 90-day time in range was 86% in 2024 and now it's 79-80%. Recently I've had days as low as 50% in range.

I have been given a box of steel cannulas to try instead of the Teflon ones. Has anyone used steel for a long time and do you get on well with them? I am put off by the fact I have to change the set every two days (rather than three) but I guess it's a price worth paying if it improves my control.
 
I used the trusteel up until they announced a shortage and got on really well with them, interesting that when I moved to the teflon sets I kept getting unexplained highs, it was suggested to me I tried changing them every 2-2.5 days and it has stopped most of those unexplained highs. It is a pain changing more often but then I remind myself I used to inject 5 times a day and it no longer seems so bad.
 
Thanks. I think, on balance, I'll just have to move over to steel cannulas. Every two days really does feel like a lot but it's a price worth paying for doing zero injections. It will just involve even more planning than before.

My control has instantly improved just from switching to a steel cannula on Monday evening. On Monday, my three-day time in range was 65%, two days later it's 77%.
 
I've been using the steel cannulas (cannulae?) for 2.5 years. Always keep them in for 3 to 4 days...
 
Good question, I just assumed there was a higher risk of infection with steel but I've never been told that.
I do leave them 2.5 and very occasionally 3 days but because I use Lyumjev it can start to congeal after 2 days.
 
sninge said:
Good question, I just assumed there was a higher risk of infection with steel but I've never been told that.
I do leave them 2.5 and very occasionally 3 days but because I use Lyumjev it can start to congeal after 2 days.
Click to expand...

Maybe I'll be a bit more elastic with my definition of 'two days' and make it more like two and a half.
 
So, as much as I want steel cannulas to work, I have experienced a mystery high. It went up to 15.5mmol/L after I over-treated a low. Even after going for a 45-minute walk and Control IQ giving me a correction, it did not go down. It's disconcerting if even steel cannulas can cause this situation.

Has anyone else experienced mystery highs with steel cannulas?
 
RobertJ said:
Has anyone else experienced mystery highs with steel cannulas?
Click to expand...
I've only ever used trusteel so have no idea whether a mystery high is caused by them. But I would expect to go high after overtreating a low and once I go up to 15 my insulin resistance goes up and I do a manual correction, as I find that control IQ doesn't cope well with my highs. (This is just what works for me, not a suggestion that anyone follows my example.)

When I started on the pump my DN recommended I try to make the cannulas last at least 3 days, as the hospital prescription assumed 2 changes a week. I was very surprised when a tandem rep told me that the trusteels were only supposed to last 2 days. (I now get 10 trusteels a month funded by the state, which is an increase.)

Currently just received a 3 day alert for my current cannula - am debating whether to do a change now or wait till tomorrow....
 
The problem I find when tslim treat a high is that the pump will only let you set insulin duration for 5 hrs when in reality for me it is 1.5hrs max, I remember a rep asking me once how it knew this... Simple, after 1.5 hrs from giving a correction and with my basals set correctly my levels will drop no more. I over ride my corrections on tslim ( which thankfully it lets us do ) if I trusted it then it would take many, many hours to correct a high.
There isn't a perfect pump yet but they are getting there. I am grateful that ive been pumping for 20yrs and learnt a lot from using the manual pumps in the past.
Ps. After 2 bent teflon cannulas in a row yesterday and 12hrs of high bloods I am sticking with the steel from now on!!
 
Back
Top