Insulin Pumps. We are starting to see them more and more, but do we know how to effectively treat a Diabetic who has one? Hawkeye has graciously allowed me to write a blog post about him, his battle with Diabetes, and his
Insulin Pump. To give you a background, Hawkeye’s Pancreas shut down when he was 21. He has no family history of Diabetes, but he rapidly began to lose weight (Went from 280lbs to 160 in less than six months), had Cataracts form in both eyes resulting in needing eye surgery to replace the lenses in his eyes…which need to be cleared of film and deposits every couple of years, and basically became very, very ill. In August of 2002, he collapsed in his kitchen and was unresponsive. Once at the hospital, it was determined his blood sugar was over 800 mg/dL. His A1C was 16.2. His mother was told that he would not make it through the night and she needed to plan a funeral for her first born by the end of the week. Hawkeye remained intubated for several weeks, came down with double Lung Pneumonia, and had a severe UTI…think beef broth urine. He pulled through, obviously, and lives to tell the tale. His Pancreas does not secrete any insulin and does not control his blood sugar at all. If he is without his Pump for longer than an hour, his blood sugar will begin to skyrocket out of control. He’s had an Insulin Pump since 2006 and he loves it. So, a bit about pumps. There are multiple pumps out there, but I will be discussing the Medtronic MiniMed pump and its assorted supplies. The insulin is contained in an internal reservoir that contains 300 units or 3mL of Insulin. The insulin is given over a period of time in what’s called a Basal Rate; a metered amount of constantly infused insulin. Right now, Hawkeye gets about eight units an hour, but it runs in like a drip through what’s called an Infusion Set. The infusion set looks like this:
There is a plastic catheter not unlike the catheter on an IV needle that rests in the Subcutaneous tissue and facilitates the delivery of insulin. The set can be placed in the Bicep, Abdomen, Thigh, or any place that you can deliver an Insulin injection. Every Diabetic has different settings for their pumps and each pump can maintain multiple Basal rates for a 24 hour period. Most pumps enable you to set up six different basal rates for a 24 hour period. The patient can take their blood sugar every two hours like a good Diabetic and enter the value into their pumps. If the number is normal, it doesn’t do anything. If the value is high, the pump will calculate out an amount of insulin to deliver to bring the BG down.
When an Insulin Pump user eats, they add up the amount of carbs in the food and they enter it into the pump. Depending on the user set parameters, the pump will administer an amount of insulin based upon the Carb to Insulin ratio. For Hawkeye, for every 3 grams of carbs, he will receive 1 unit of insulin. They are also asked to input a BG reading. This is where you get a lot of your Hypoglycemic episodes; a person over calculates their carbs along with having a borderline low blood sugar. In a few minutes, you’ll have someone unconscious in their Spaghetti. Humalog, which is what many Insulin Pump users use, is a very rapid acting Insulin. You can see a change in the Blood Glucose values in approximately 5-7 minutes, more or less depending on just how much Insulin they are getting in one shot. Someone doing regular injections, who are getting their whole 20 units at once will have a quicker change than someone who is using a Pump, but a pump user can still experience a dramatic low while eating, especially after eating if they do not stop the bolus if they stop eating before they’ve eaten the proper amount of carbs.
Now, the fun comes in when we as EMS Providers need to treat a Diabetic emergency when someone is wearing a pump. The newest version of the Insulin Pumps have Continuous Glucose Monitoring (CGM) which takes a Glucose reading every fifteen minutes. The pump itself stores the information and can tell the person if the sugar is high, low, or even show if the BG is going to go high or low by predicting a trend. You can access the log by pressing the Esc button on the pump:
Older style pumps will not stop delivering Insulin no matter the BG that’s input. The newest version with the CGM will do something called a Threshold Suspend. This is when the user has set a lower limit for the blood glucose and the pump will shut off and stop delivering insulin for a finite period of time, but will restart once the time period has passed and the BG is above the lower limit. The Threshold Suspend goes off the BG reading from the CGM. If there is a weak signal or the pump has lost communications with the sensor, the pump will not shut off. There’s an alarm that sounds and a message pops up that says, I have Diabetes, Call for Emergency Assistance., but only if the pump and sensor are communicating.
One of the biggest things a Paramedic needs to do is to Suspend the pump before trying to raise the blood sugar. Since Insulin is running into the body on a continual basis, you will be fighting an uphill battle against the machine. To suspend the pump, you can hit the Act button, press the down button to highlight Suspend, then hit Act again. You can do this on the newer pump if you are unsure if the pump has suspended or not. You can then treat Hypoglycemia accordingly.
If the pump is not suspended, then you can spend a very long time trying to raise the blood glucose depending on how low the value is. Hawkeye recently had a BG of 27. He was shockingly not unresponsive, but he was extremely altered. The pump had not suspended itself as the signal from the CGM to the Pump was weak, so it was still delivering his basal rate on schedule. After two amps of D50 and twenty minutes, his BG was only 32. Once the pump was shut off, it went from 32 up to 88 in about fifteen minutes. Now, mileage may vary on this as I’ve seen Diabetics who haven’t suspended their pumps have a normal increase in blood sugar in response to D50. I think a lot of it has to do with what caused the low; if it’s a Bolus mistake
In the end, your mileage may vary with this advice. Your Local Protocols may say that EMS are not allowed to mess with an Insulin pump, but you can always ask a friend or family member with the patient to operate the pump if it’s seeming like you are getting nowhere with raising the blood sugar. Many patients who have pumps are very good at keeping track of their blood sugar, but can experience very dramatic lows due to just how the insulin is delivered.
Have fun and Be safe!