GCSE question for Dia-Maths

[helli]

Much of managing diabetes involves maths.
There is carb counting when packets tell you per 100g, or worse, carbs when cooked.
Then there is insulin dose calculation which depends upon time of day, current BG and more.
Exercising with diabetes can add another section to the GCSE paper when you need to consider duration, intensity and fitness levels.

Today, I came across another question.

My pump needs to be changed every 3 days.
I am currently in Las Vegas.
Las Vegas is 8 hour behind UK.
My return flight leaves at 11:40 on Thursday, landing in LHR at 10:40 local time. I change planes at LAX.
If I apply a new pump at 6am Vegas time today, where will I be when I next need to change it?

(Don't get excited about Vegas. I am here for business and, out of travel, sleep and work, I am spending most time travelling.)

 

[silver minion]

Makes my brain ache just reading about it @helli Do you keep your watch to GMT while you are travelling across several time zones?

 

[Thebearcametoo]

When it suits you, when your pump stops working or if your cannula stops working.

We used to be able to stretch a pump change to 4 or sometimes 5 days but he’s currently eating like a stereotypical teenage boy so he’s usually run out of insulin by about 2 1/2 days.

 

[Lucyr]

My pump needs to be changed every 3 days.

Surely it doesn’t need changing every 3 days to the minute/hour, it’s every 3 days ish before it runs out of insulin and when suits you that day?

 

[helli]

Do you keep your watch to GMT while you are travelling across several time zones?

I always try to get into local time.
The rest of life - meal times, conference agenda, people I work with - are in local time. I cannot do what 8 need to do if I am 8 hours ahead of all that. I would be having breakfast at 3pm and evening networking at 4am). I might as well stay at home.
Thankfully, my pump switches to local time when I arrive. Otherwise DP would be kicking in when my basal is too low.

 

[helli]

Surely it doesn’t need changing every 3 days to the minute/hour, it’s every 3 days ish before it runs out of insulin and when suits you that day?

It is not exactly 3 days (72 hours) but it also not until the insulin runs out. For my patch pump, I need to be aware of the battery life. The other reason pumps need to changed is cannula changing and insulin integrity.
My pump has 8 hours grace (so I have 80 hours to change) but with a journey time of more than 12 hours, it is something I have to consider.

Edited to add: for the other reasons, I do not fill my pump but instead put enough insulin in it to comfortably last 3 days. I always have some left in the pump but that is better than needing to do a 5 minute set change before eating the dinner I am cooking/is in front of me.

 

[Lucyr]

My pump has 8 hours grace (so I have 80 hours to change) but with a journey time of more than 12 hours, it is something I have to consider.

What I mean is, if it needs changing ”on day 3 + 8 hrs grace” then that gives you 32 hours in which to change it (the 32 hours up to the ultimate end time). You’re only traveling for 12 ish hours so there’s another 20 hours in which to change it. So worrying about where you’ll be when it’s due for changing is overkill.

 

[SB2015]

Brilliant @helli. A bit more complex than the questions that I use to set my class before lunch. They used to calculate my bolus based on BG, insulin sensitivity, carbs and my insulin carb ratios. T1 awareness and good use of ratios.

 

[helli]

I have made it to LA with 16 hours left on my pump and the onward flight it saying it is on time.
I think it will make it back to the UK with no need for me to find a private corner to change it in the airport or plane.
Whilst I would inject in public, I can't get to my pump site easily without exposing parts that should not be exposed.
All looking good for now.