Insulin Duration Setting?

[jenet]

OK, this is Pump Day 4 and I am really trying hard to hold onto my patience but I am very frustrated, and ready to scream or cry or throw something... :argh:

On MDI using Humalog, if I needed to correct my BG after 3 hours, I would calculate the (actual BG - target BG) / my ISF and it pretty much worked 99% of the time with good results another 3 hours later - a nice solid number, not too low. I can't remember going low after a correction after my first year. (I was really good at doing corrections 10 years later.)

Now, here I am with my Animas pump, and most of the time the da*n ezBG correction bolus wizard says I need no correction at 3 hours post meal (that's right - zero insulin) or very little because it thinks I have too much insulin already on board. If it thinks I need any, it's generally too low, and I end up having to do a second correction 3 or 4 hours later. In desperation, I have resorted to ignoring the ezBG/IOB net bolus recommendations and overriding the bolus amount based on my best judgement.

For Pump Start, my CDE/pump trainer insisted on changing my Insulin On Board active duration setting to 4 hours to avoid stacking. (I had set it to 3.5 before Pump Start.) The Pumping Insulin book says Humalog's duration is generally 3.5 hours (YMMV), and my personal experience has been to use 3 hours to great effect while on MDI.

Am I out of my mind thinking the problem is that 4 hours is just too long, and it is undercalculating the suggested bolus because it thinks I have more insulin on board than I really do at that point? :stupido:

I'm hoping you folks' thoughts will shed some light on this. Please?

:(
j

[MarkMunday]

..... Am I out of my mind thinking the problem is that 4 hours is just too long, and it is undercalculating the suggested bolus because it thinks I have more insulin on board than I really do at that point? :stupido:

I'm hoping you folks' thoughts will shed some light on this. Please?
My experience has been that Novorapid peaks at about 50 minutes and is just about all finished after 2 hours. I know that other peopl respond to this insulin very differently. But I have always worked on this basis when doing corrections. The CGMS graphs seemed to support this.

Of couse we are all different. And you need to set the parameters on your pump according to your unique requirements.

Cheers,

Mark

[spike]

OK, this is Pump Day 4 and I am really trying hard to hold onto my patience but I am very frustrated, and ready to scream or cry or throw something... :argh:

On MDI using Humalog, if I needed to correct my BG after 3 hours, I would calculate the (actual BG - target BG) / my ISF and it pretty much worked 99% of the time with good results another 3 hours later - a nice solid number, not too low. I can't remember going low after a correction after my first year. (I was really good at doing corrections 10 years later.)

Now, here I am with my Animas pump, and most of the time the da*n ezBG correction bolus wizard says I need no correction at 3 hours post meal (that's right - zero insulin) or very little because it thinks I have too much insulin already on board. If it thinks I need any, it's generally too low, and I end up having to do a second correction 3 or 4 hours later. In desperation, I have resorted to ignoring the ezBG/IOB net bolus recommendations and overriding the bolus amount based on my best judgement.

For Pump Start, my CDE/pump trainer insisted on changing my Insulin On Board active duration setting to 4 hours to avoid stacking. (I had set it to 3.5 before Pump Start.) The Pumping Insulin book says Humalog's duration is generally 3.5 hours (YMMV), and my personal experience has been to use 3 hours to great effect while on MDI.

Am I out of my mind thinking the problem is that 4 hours is just too long, and it is undercalculating the suggested bolus because it thinks I have more insulin on board than I really do at that point? :stupido:

I'm hoping you folks' thoughts will shed some light on this. Please?

:(
j

I can't comment on the 4 hours being "too long", BUT, the longer it is set for, the less corrective bolus it will allow, because the pump thinks you have more remaining insulin.

[Belinda]

I have a MM with a bolus wizard....here is what I do and needless to say IT works for me....

After I eat or whenever I get ready for bed or just when ever....I check my BS...I then put it into the pump and it give me the data on a screen about how many carbs, correction insulin needed and active insulin. If I need more then I just hit ACT and go about my business...but sometimes I found that goofy me over estimated a meal and had toooooooo much insulin...at that point I just did a temp basal for the duration needed....Let me repeat myself.....this works for me.;)

[jenet]

My experience has been that Novorapid peaks at about 50 minutes and is just about all finished after 2 hours. I know that other peopl respond to this insulin very differently. But I have always worked on this basis when doing corrections. The CGMS graphs seemed to support this.

Of couse we are all different. And you need to set the parameters on your pump according to your unique requirements.

Cheers,

Mark
OK, I am not out of my mind. There is at least one other person in this world whose duration is less than 4 hours. :smile:
Thanks much,
j

[jenet]

I have a MM with a bolus wizard....here is what I do and needless to say IT works for me....

After I eat or whenever I get ready for bed or just when ever....I check my BS...I then put it into the pump and it give me the data on a screen about how many carbs, correction insulin needed and active insulin. If I need more then I just hit ACT and go about my business. ... Let me repeat myself.....this works for me.;)
This sounds very similar to the way the Animas bolus wizard works. My problem is that it never recommends enough, and sometimes recommends none. I have tried waiting it out to see if it is right, and it isn't. So, then I am even higher. Do you mind me asking how long you have your active insulin duration set to?

Thanks much,
j

[koblenz]

Well, I have a Cozmo and mine is set to 3 hours. I use Novolog. I did a lot of monkeying with it in the beginning and this seems to be the magic number for me. Initially my Endo said set it to 4, but I was frequently under correcting at that setting.

One thing I have found for ME, is that the correction and duration are also affected by what I have eaten. For most foods, 3 hours is fine. But when I have a meal that is a little higher on the glycemic index, then I correct a little less at 3 or 4 hours. If I did a full correction, I would end up being a little low later.

Anyway, there is my 2 cents.

[jenet]

Well, I have a Cozmo and mine is set to 3 hours. I use Novolog. I did a lot of monkeying with it in the beginning and this seems to be the magic number for me. Initially my Endo said set it to 4, but I was frequently under correcting at that setting.

One thing I have found for ME, is that the correction and duration are also affected by what I have eaten. For most foods, 3 hours is fine. But when I have a meal that is a little higher on the glycemic index, then I correct a little less at 3 or 4 hours. If I did a full correction, I would end up being a little low later.

Anyway, there is my 2 cents.
Awwww, it was worth at least 25 cents. ;) I'm hoping it will be that simple an explanation, and that after changing the IOB Duration setting on Monday, things will be smoother.

Thanks much for sharing your cents (sense) on this question. :laugh:
cheers,
j

[Shotokan]

The other things to check are the ISF and target BG programmed into your pump. Are they set properly?

[jenet]

The other things to check are the ISF and target BG programmed into your pump. Are they set properly?
Probably close enough to work on fine-tuning the basal rates, since we used the ISF and target that was working on MDI. Once the basal rates get nailed down, then I will work on fine-tuning my I:C and ISF, as they may be affected by no longer having Lantus in my system (which was 2 units/day higher than my current basal).

My prime theory at this point is the duration needs to be changed from 4 hours to 3. If I ignore the ezBG wizard, and use my ISF and target for a BG correction at 3 hours after eating, the correction works perfectly. (And if I have a good BG pre-meai, everything is fine post-meal with no correction needed.)

But you're right, I will need to test my ISF for fine-tuning the pump settings. :)

cheers,
j

[nantomsuethom]

Thomas uses the Animas 1200 (before that the 1000) he has always had his IOB set at 3 hours. This seems to be the best for him.

One of the students I take care of has a MiniMed I think 700?. I tried to figure out her active insulin setting and couldn't. She has a lot of active insulin 4 hours after a bolus. Her mom called minimed and they told her that it could not be changed and was set at 10 hours!. Someone else told her 6 hours. It was preset with a ISF of 250. That she was able to lower. Needless to say the little girl (6) was having lots of high #s.

[jenet]

Thomas uses the Animas 1200 (before that the 1000) he has always had his IOB set at 3 hours. This seems to be the best for him.

One of the students I take care of has a MiniMed I think 700?. I tried to figure out her active insulin setting and couldn't. She has a lot of active insulin 4 hours after a bolus. Her mom called minimed and they told her that it could not be changed and was set at 10 hours!. Someone else told her 6 hours. It was preset with a ISF of 250. That she was able to lower. Needless to say the little girl (6) was having lots of high #s.
Totally shocked!! How on earth did she ever get any correction boluses to work on her pump? I thought that even the tail of rapid-acting insulins was well gone by 6 hours. I don't know anything about kids' ISFs, so I wouldn't know if 250 was bad, but it sounds awfully darn high. I hope she eventually got things straightened out, and is not having so many highs now?

cheers,
j

[dws]

Minimed does NOT have a 700 pump, does have a 712 and a 715.
I'm upgrading to a 515 ( the 515 & 715 are the same except for the size of the resovoir) this week and it will allow the insulin to be set at different times. (from 2 to 8 hours the factory setting is for 6 hours)

don

[Shotokan]

You might be interested in this article, which discusses pump settings for insulin duration. Apparently, Animas pumps deal with it differently from Paradigm and Cosmo pumps:
http://diabetesnet.com/diabetes_technology/pump_durinslact_danger.php?

[jenet]

You might be interested in this article, which discusses pump settings for insulin duration. Apparently, Animas pumps deal with it differently from Paradigm and Cosmo pumps:
http://diabetesnet.com/diabetes_technology/pump_durinslact_danger.php?
Yes, I read that article earlier this weekend. It doesn't match my personal experience, but it was interesting. YMMV.

I've been doing 18 finger sticks a day the last 5 days and my poor fingers are so sore at this point: wake up, 3 meals (before, 2hrs, 3 hrs, 4 hrs, 5 hrs), midnight and 3 am. What I have documented by doing all this testing is that after 3 hours my BG almost never goes down by more than 5-10 mg/dl (within the range of accepted meter variability from one test/test strip to the next). This matches my MDI experience with Humalog that my BG is stable 3 hrs after meal/bolus, unless I engage in some prolonged activity (i.e. 2-3 hours mall shopping, etc.).

cheers,
j

[Shotokan]

I just found another piece at http://www.integrateddiabetes.com/Fall2004.doc

The information in this article is slightly different from the information at diabetesnet, especially for Animas pumps shipped after Sept. 20, 2004. Here is the section that is relevant. No wonder people get confused about how to set insulin duration!

What’s Left?: Unused Insulin Calculations on Pumps

One of the nicer features on the latest insulin pumps is the “bolus calculator”. Included in the pump’s bolus calculation is an estimate of how much insulin is still active from previous boluses – what we like to call “unused insulin”. The pumps will deduct unused insulin from any amount needed to correct a high blood sugar.

Now here’s the tricky part: each pump figures unused insulin in a different way. Understanding how your pump figures unused insulin is important to your decision-making process.

The Cozmo pump from Smiths Medical uses a variable linear equation for figuring out how much insulin is “used up” and how much is still active. It is variable because the user can select the duration of insulin action, from 2 to 8 hours (3-4 hours is most common for those using Humalog or Novolog in their pumps). It is linear because the pump assumes that the insulin absorbs and acts at a steady, unwavering rate. For example, if you set the duration of insulin action at 3 hours, the pump will assume that 33% is used up each hour. For a 5-hour duration of action, it assumes that 20% is used up each hour.

The Paradigm 512 and 712 pumps from Medtronic/MiniMed have an action curve for the insulin based on data provided by the insulin manufacturers. This approach assumes that it takes about 6-7 hours for the insulin to disappear completely, with most of the insulin used between 1 and 4 hours, and only a small amount used during the first hour and final three hours.

The new 1200 pump from Animas combines the features of the other two: a variable action curve. The Animas pump’s unused insulin feature utilizes an action curve similar to the one on the Paradigm pump while allowing the user to select a preferred duration of action, from 1½ to 6 hours. However, the duration set by the user may not be the point at which the insulin stops working. With pumps shipped prior to September 20, 2004, the duration set is the point at which 30% of the insulin is remaining, and the “tail” of action sets in. With pumps shipped after September 20, 2004, the duration set is the point at which the insulin stops working.

[jenet]

I just found another piece at http://www.integrateddiabetes.com/Fall2004.doc


The information in this article is slightly different from the information at diabetesnet, especially for Animas pumps shipped after Sept. 20, 2004. Here is the section that is relevant. No wonder people get confused about how to set insulin duration!

What’s Left?: Unused Insulin Calculations on Pumps

One of the nicer features on the latest insulin pumps is the “bolus calculator”. Included in the pump’s bolus calculation is an estimate of how much insulin is still active from previous boluses – what we like to call “unused insulin”. The pumps will deduct unused insulin from any amount needed to correct a high blood sugar.

Now here’s the tricky part: each pump figures unused insulin in a different way. Understanding how your pump figures unused insulin is important to your decision-making process.

The Cozmo pump from Smiths Medical uses a variable linear equation for figuring out how much insulin is “used up” and how much is still active. It is variable because the user can select the duration of insulin action, from 2 to 8 hours (3-4 hours is most common for those using Humalog or Novolog in their pumps). It is linear because the pump assumes that the insulin absorbs and acts at a steady, unwavering rate. For example, if you set the duration of insulin action at 3 hours, the pump will assume that 33% is used up each hour. For a 5-hour duration of action, it assumes that 20% is used up each hour.

The Paradigm 512 and 712 pumps from Medtronic/MiniMed have an action curve for the insulin based on data provided by the insulin manufacturers. This approach assumes that it takes about 6-7 hours for the insulin to disappear completely, with most of the insulin used between 1 and 4 hours, and only a small amount used during the first hour and final three hours.

The new 1200 pump from Animas combines the features of the other two: a variable action curve. The Animas pump’s unused insulin feature utilizes an action curve similar to the one on the Paradigm pump while allowing the user to select a preferred duration of action, from 1½ to 6 hours. However, the duration set by the user may not be the point at which the insulin stops working. With pumps shipped prior to September 20, 2004, the duration set is the point at which 30% of the insulin is remaining, and the “tail” of action sets in. With pumps shipped after September 20, 2004, the duration set is the point at which the insulin stops working.


I had not found that detailed comparison and explanation about how the Animas Insulin On Board Duration calculation works, and it will be quite helpful.

Thank you very much indeed. :flowers:
cheers,
j

[spike]

I just found another piece at http://www.integrateddiabetes.com/Fall2004.doc

The information in this article is slightly different from the information at diabetesnet, especially for Animas pumps shipped after Sept. 20, 2004. Here is the section that is relevant. No wonder people get confused about how to set insulin duration!

What’s Left?: Unused Insulin Calculations on Pumps

One of the nicer features on the latest insulin pumps is the “bolus calculator”. Included in the pump’s bolus calculation is an estimate of how much insulin is still active from previous boluses – what we like to call “unused insulin”. The pumps will deduct unused insulin from any amount needed to correct a high blood sugar.

Now here’s the tricky part: each pump figures unused insulin in a different way. Understanding how your pump figures unused insulin is important to your decision-making process.

The Cozmo pump from Smiths Medical uses a variable linear equation for figuring out how much insulin is “used up” and how much is still active. It is variable because the user can select the duration of insulin action, from 2 to 8 hours (3-4 hours is most common for those using Humalog or Novolog in their pumps). It is linear because the pump assumes that the insulin absorbs and acts at a steady, unwavering rate. For example, if you set the duration of insulin action at 3 hours, the pump will assume that 33% is used up each hour. For a 5-hour duration of action, it assumes that 20% is used up each hour.

The Paradigm 512 and 712 pumps from Medtronic/MiniMed have an action curve for the insulin based on data provided by the insulin manufacturers. This approach assumes that it takes about 6-7 hours for the insulin to disappear completely, with most of the insulin used between 1 and 4 hours, and only a small amount used during the first hour and final three hours.

The new 1200 pump from Animas combines the features of the other two: a variable action curve. The Animas pump’s unused insulin feature utilizes an action curve similar to the one on the Paradigm pump while allowing the user to select a preferred duration of action, from 1½ to 6 hours. However, the duration set by the user may not be the point at which the insulin stops working. With pumps shipped prior to September 20, 2004, the duration set is the point at which 30% of the insulin is remaining, and the “tail” of action sets in. With pumps shipped after September 20, 2004, the duration set is the point at which the insulin stops working.



Thanks for posting that info on IOB. I'm considering a 1250 to replace my out of warranty MM.

[nantomsuethom]

Minimed does NOT have a 700 pump, does have a 712 and a 715.
I'm upgrading to a 515 ( the 515 & 715 are the same except for the size of the resovoir) this week and it will allow the insulin to be set at different times. (from 2 to 8 hours the factory setting is for 6 hours)

don
Oops.. She has a 712.

[Cyborg]

I'm using the Animas 1250 with Novalog also and I have my duration set to 3 hours. While on MDI, I noticed the humalog had a duration of approx 2 to 2 1/2 hours and the Novalog was a little longer, approx 3 hours for me. So this setting was easy for me while transitioning to the pump and the trainer had no problem with setting it to 3 hours for Novalog...

[jenet]

I'm using the Animas 1250 with Novalog also and I have my duration set to 3 hours. While on MDI, I noticed the humalog had a duration of approx 2 to 2 1/2 hours and the Novalog was a little longer, approx 3 hours for me. So this setting was easy for me while transitioning to the pump and the trainer had no problem with setting it to 3 hours for Novalog...
I'm getting really great results with my new basal rates, and just changed my I:C last night after meeting with my CDE, so I'm going to wait one more week before doing anything about the duration. I don't want to change too much too fast, but I really appreciate your input and may also change my duration to 3 hours next week if the ezBG/IOB net continues to suggest corrections that seem too low.

Thanks much,
j