Diabetes & Pregnancy: Using CamAPS FX Hybrid Closed Loop (HCL) in Pregnancy

Some Basics on how the Algorithm works

• The pump delivers an “extended bolus” of insulin every 8-12 minutes to achieve the personal glucose target you have set.
• The pumps default glucose target is 5.8mmol/l but can be personalised between 4.4–11.0mmol/l. We will support you in setting the personal glucose target that is for you at each stage of your pregnancy.
• The algorithm calculates how much insulin to give using the following:
  • Your body weight (please update after each ultrasound scan in the Settings and Change weight menu)
  • Total daily dose insulin (automatically updated every day around midnight)
  • Personal glucose target set
  • “Learned” insulin needs
  • Current glucose level and patterns over the last 24 hours
  • Carbohydrate on board
• If the algorithm predicts your glucose will drop below your target glucose, it will reduce or stop the ‘basal’ insulin delivered to reduce the chance of hypoglycaemia (a hypo).
• If the algorithm predicts your glucose will rise above your target glucose, it will increase the ‘basal’ insulin delivered to correct it back down.
• The insulin to carbohydrate ratios programmed into the CamAPS FX Apps bolus calculator determine the dose of pre-meal insulin that you are offered. These ratios are often changed as the pregnancy progresses.
• It is important to give your meal bolus at least 10-15 minutes before eating. This timing might need to be reviewed as the pregnancy progresses.
• When in Auto mode, the algorithm does not use the basal rates programmed into the pump. However, it is important these are entered and kept updated, in case you need to come out of Auto mode for any reason (e.g. when the sensor is warming up). Your correction factor, glucose target and active insulin time in your Bolus calculator settings are only used when you request a manual correction. The algorithm has its own settings which are continually updated.

Ease-off should be used for times when you are more sensitive to insulin, such as when you are physically active or in hot weather. Using Ease-off will make the algorithm more relaxed to reduce the risk of going low. Ease-off can be programmed to start now or up to 24 hours later. It can run for up to 24 hours at one time. Ideally, start Ease-off at least 60-90 minutes before exercise and run it during and potentially after the activity for up to 90 minutes.

Boost makes the algorithm more proactive for times when you need more insulin, such as when you are running high due to illness (no ketones), if you need steroids or have had an infusion set failure. Boost is still aiming to reach your personal glucose target, so will stop as soon as the glucose levels are back in range. Boost can be programmed to start now or up to 24 hours later. It can run for up to 24 hours at one time. We recommend that if you will not reach your target glucose level (e.g. below 7.8mmol/l after 1 hour of eating), put Boost on for 2-4 hours and reassess regularly. Always check for ketones when running high and if Boost does not have an effect, please consider doing an infusion set change. If you need to use Boost frequently, your insulin to carbohydrate ratio and bolus timing might need to be reviewed.

Boost does not replace sick day rules. It is important to come out of Auto mode if ketones are present at 1.0mmol/l or above. There is more information on ketones and illness below.

The following Top Tips will help the CamAPS algorithm to work at its best for you

Trust the system

Starting on a HCL system can take some adjusting to. The algorithm takes up to 3 weeks to learn and adjust insulin delivery specific to your needs.

Timing bolus insulin for food 10–15 minutes beforehand

• Giving your bolus insulin at the right time makes a big difference to keeping your glucose stable and in the healthy pregnancy range.
• Insulin absorption slows down during pregnancy, so it becomes even more important to give your insulin BEFORE you eat.
• The timing of insulin before meals may need to extend as your pregnancy progresses. Though most women find 10-15 minutes works well throughout the whole of their pregnancy, it is best to learn from experience.
• If the bolus is given as you eat, or after you eat, you are more likely to rise above range at 1 hour after the meal and then drop to a hypo around 90-150 minutes.

Enter ALL carbohydrate eaten into the CamAPS App

• It is important you enter all carbohydrate eaten into the CamAPS App, so the algorithm knows a rise in glucose is related to carbohydrate eaten, rather than you needing more basal insulin at that time of day.
• For most meals and snacks you can enter the carbohydrate into the CamAPS App bolus calculator (knife and fork icon – symbol in middle top home screen).
• Add meal function (found in drop down menu) is used for any additional carbohydrate consumed outside of main meals e.g. hypo treatments or snacks (20g or less carbohydrates). The Add meal (meal or snack option) is useful when eating small amounts of carbohydrates when active, to prevent a low glucose, or if you have eaten extra after the main meal insulin has been delivered. This will allow the algorithm to adjust the insulin to cover the carbohydrates, but only when the glucose rises.
• If carbohydrate (main meal, snack or hypo treatment) is not added to the CamAPS App you will increase the chance of having a hypo.
• For meals when you would previously have used an extended bolus or if you are unsure, you will eat all of your meal, you can give 50% of the insulin via the bolus calculator (knife and fork icon) before you eat and then add the other 50% via Add meal. The Slowly absorbed meal option can be used for meals where you have tended to notice a delayed glucose rise. This is usually seen with high fat and protein meals or very low glycaemic index foods.
• For hypo treatment – use Add meal enter carbohydrate amount and select Hypoglycaemia treatment.
• Avoid correcting post meal highs: avoid entering ghost carbohydrates.
• Consider using Boost to limit the glucose excursion after a meal. If glucose is above 7.8mmol/l at your 1-hour blood glucose review, then please consider putting on Boost for 2 hours to help bring your blood glucose back into range.

Accurate carbohydrate counting

• The algorithm can “mop up” some error in carbohydrate counting, but it will work most effectively when carbohydrate counting is accurate.
• If you are unsure of the carbohydrate in the meal you are about to eat (such as a meal out) and you underestimate, you can add Boost for 4 hours to give the algorithm permission to give more insulin if needed.
• If you would like to refresh your carbohydrate counting skills, please try one of the online courses listed below:
  • Breakthrough T1D (opens in a new tab)
  • Bertie Diabetes (opens in a new tab)
  • DAFNE 2 hours online carbohydrate counting course (please ask for more details if interested)

Carbohydrate eaten, type and quantity

• To help keep post meal blood glucose within the healthy pregnancy range, it is important to consider the type and quantity of the carbohydrates you consume.
• The algorithm will struggle to cover rapidly rising glucose after eating highly processed carbohydrates, so choose slowly absorbed, high fibre, unprocessed types.
• The algorithm will struggle to cover large carbohydrate loads. The limit for most pregnant women is 15-20g at breakfast and 40-50g at lunch and evening meal. As your pregnancy progresses and you become more insulin resistant, these amounts may need to lower.

Personal glucose target

• Your personal glucose target (different to the bolus calculator glucose target) is one of the main drivers for how much insulin the algorithm will give you.
• We will help you set the right personal target as your pregnancy progresses.
• The following are suggested starting points for personal glucose targets in each trimester:

1st trimester aim for 5.5mmol/l since insulin sensitivity is higher during this time.

2nd trimester (or earlier) aim for 4.5-5.0mmol/l as insulin resistance starts to increase.

We recommend using 4.5mmol/l from 22:00h to 07:00 and 5.0mmol/l during the day.

• After giving birth 8.0mmol/l can be used unless otherwise advised.
• Remember you can set a different personal glucose target overnight to during the day. If you are struggling with frequent hypos, increase the personal glucose target by 1.0mmol/l for a few days. Once hypo free you can try taking it back down again.

Cannula changes

• Every 2 days during pregnancy ensure you rotate sites. Please notify us as soon as possible if you notice any skin irritation, infection or skin reactions at the infusion set site.

Activity or exercise

• Set Ease-off on the CamAPS App for 60-90 minutes before the activity and consider leaving it on for up to 90 minutes after the activity.
• It is not recommended to use large carbohydrate amounts to cover exercise, as this will increase automated insulin delivery and increase the chance of a hypo.
• If you need to take in extra carbohydrate during or before the activity, we recommend ‘drizzle feeding’ up to 8g of carbohydrates (e.g. 2 x jelly babies) every 20 minutes as required. It is recommended these carbohydrates are entered into the CamAPS App as hypo treatment to prevent extra insulin being given.

If your pump is disconnected for more than 15 minutes, please turn off Auto mode and suspend the insulin delivery. We would not recommend being disconnected from your pump for more than an hour.

Hypoglycaemia (hypo)

Less carbohydrate is used to prevent a hypo: you typically need 4-5g of rapid acting carbohydrate if glucose 6.0mmol/l or less with a ↓ trend arrow.

Whereas to treat a hypo (3.5mmol/l or less), 8-10g of rapid acting carbohydrate is needed.

Preventing hypos

Most hypos occur within 90-150minutes after a meal during pregnancy, due to needing larger doses of insulin with the meal to achieve the post meal target. Below are some considerations that can help reduce your chance of a hypo.

• Ensure insulin is given 10-15 minutes before the meal.
• It can be helpful to split meals (if having a sandwich and yogurt; have the sandwich at the mealtime and have the yogurt 30-60 minutes later) but still give your full bolus upfront.
• Check sensor glucose at 90-120minutes after the meal and if below 6.0mmol/l with arrows down, have a small carbohydrate snack with no insulin. Remember to add this via Add meal (Meal or snack) function on the CamAPS App.

Treating hypos:

It can be helpful to review the insulin on-board to help decide how much carbohydrate you need.

• If no active insulin on-board start with 10g carbohydrate.
• If you still have active insulin on-board from a previous meal you will need more carbohydrate.
• Ease-off can be used if you have had a severe or series of hypos.

Remember: always add hypo treating carbohydrates into the CamAPS App via Add meal and Hypoglycaemia treatment.

Managing hyperglycaemia

Illness and Sick day Rules

• Boost can be used for mild illness, pain or stress. We would recommend setting it for a minimum of 2 hours.
• If glucose levels are consistently running above 10.00mmol/l and/or you have ketones present at 1.0mmol/l or above

Please come out of Auto mode and follow the pregnancy insulin pump sick day rules.

Unexplained above range readings

If your glucose levels are running above range for more than 3 hours, you can see the algorithm is working hard without impact and you are unable to explain why (e.g. forgotten insulin dose) you should do an infusion set change as soon as possible.

Travel / flying

HCL systems rely on Bluetooth to communicate with the sensor.

On take off

• Disconnect pump when in airplane mode
• As soon after take-off as able, reconnect pump and turn airplane mode off

On landing

• Disconnect pump when in airplane mode
• As soon after landing as able, reconnect pump and turn airplane mode off

If travelling to a hot country, especially if you plan to be more active, use Ease-off for the first few days as your body acclimatises or set a higher personal glucose target.

Changing time zones: this should happen automatically on your phone.

Connection issues between the Ypsopump and CamAPS App

It is helpful to turn your phone off and back on again once weekly as this can help to prevent connection issues. If you are having connection issues, below are some suggestions to resolve it. If the issues continue, please contact Camdiab and submit a log (this allows Camdiab to review your data and identify the issue). You can submit a log via the CamAPS App (main menu > contact > submit log).

Ways to fix Bluetooth on/off problems:

• Enable airplane mode, then turn on/off Bluetooth
• Reboot your phone, then turn on/off Bluetooth
• Search Reset Network Settings in Settings, tap RESET NETWORK SETTINGS and then turn on/off Bluetooth

* Reminder: resetting network settings will remove the connection record of WLAN, Mobile network and Bluetooth

• Search Reset Phone in Settings, tap RESET PHONE, then turn on/off Bluetooth

* Reminder: resetting phone will delete all your data, please back up your data in advance.

Check battery optimisation setting:

• Phone settings > Apps > Settings > Special access > Ignore battery optimisation >Select allow
• Check that the app is allowed to work in the background
• Select allow for LOCATION

Failure modes/Troubleshooting

Please refer to the failure modes/troubleshooting section in the CamAPS user manua (opens in a new tab)l on page 73.

This will include troubleshooting advice regarding the CamAPS FX App, insulin pump, CGM, and the cloud upload portal.

Contacts:

CamDiab

CamDiab Support is available during business hours: Monday - Friday: 9am – 5pm GMT.

• Email: support@camdiab.com
• Telephone: (+44) 020 3695 3780

If out of hours issues arise with the CamAPS FX system, please revert to open-loop insulin pump therapy and CGM.

For insulin pump-related issues, please contact your insulin pump company.

In the UK:

• Dana insulin pump - Advanced Therapeutics UK (ATUK) (opens in a new tab)
• mylife YpsoPump - Ypsomed (opens in a new tab)

Ypsomed

Technical support line is available 24/7 for urgent assistance

Technical support: 0344 8567820

Insulin pump insurance

The insulin pump companies will replace the pump when broken if a technical/mechanical fault is found or through general wear and tear during the 4 years of warranty. However, accidental damage or loss due to theft is not covered. You will be expected to personally pay for the replacement of the pump in these cases. Most pumps cost between £2500 and £3000 to replace, so we strongly recommend that you insure your pump under your household insurance or via one of the specialist insulin pump insurance companies.

The phone handset provided by Ypsomed cannot be replaced if lost or damaged. A replacement will need to be procured by the user.