Posted by Bill Sandweg on 30 November 2020.
If you read these posts with any regularity, you know my 10 year old grandson is a Type 1 diabetic. He just “celebrated” his “diaversary,” marking 7 years since his diagnosis on the Labor Day weekend in 2013. He manages his glucose levels with the help of an insulin pump manufactured by Medtronic. There have been major problems with a recent updated version of the pump.
For those who may not be familiar with Type 1 diabetes (Type II is far more common), it is the result of an autoimmune process in which the body’s immune system attacks and destroys the insulin producing cells in the pancreas. Insulin is the hormone that converts glucose (sugar) in the bloodstream into energy the body needs to operate. If there is no or too little insulin in your bloodstream, your body cannot use the glucose to produce energy. It must start cannibalizing body fat for energy and dumping excess glucose in the urine. If not diagnosed and corrected, the process is fatal within a few months.
If you are in good health, your pancreas monitors your blood glucose levels and decides how much insulin you need to keep your blood sugar levels in the proper range. Too much glucose in the blood is called hyperglycemia. The more carbohydrates you consume, the more glucose you will have and the more insulin you need. If your blood sugar levels fall too low (hypoglycemia), the pancreas will release glucose into the blood to raise the level into the appropriate range. Too much glucose in the blood will cause damage over the long term, including blindness and nerve damage in the extremities. Too little glucose causes immediate problems, which can include confusion, loss of consciousness and even death. Type 1 diabetics always keep something with them to quickly raise blood sugar, in the event of a hypoglycemic event. Keeping the blood glucose levels from going too high is important but not as critical as keeping them from going too low.
The insulin pump is a major development in the treatment of diabetes. It delivers insulin into the bloodstream without the necessity for repeated injections. At the present time, the patient must program the pump and tell it how much insulin to deliver.
As with most other things, it is almost impossible to replicate the fine balance our bodies have developed to deliver just the right amount of insulin. No matter how careful a diabetic is in watching what she eats and calculating the proper dose of insulin to enter into the pump, it may not be enough or it may be too much. The holy grail for insulin pumps is what is called the “artificial pancreas,” a closed loop system in which the system regularly checks glucose levels in the blood and orders the pump to deliver insulin or glucose to keep blood sugars in the appropriate range. The technology already exists to do this but the FDA is concerned about the reliability of the system, which includes the reliability of the pump itself, and, until it is satisfied that all parts of the system are reliable, it will not authorize marketing and sale of the closed loop system. This is where Medtronic’s current pump problems come in.
Medtronic is one of the major manufacturers of insulin pumps and sensors. In 2016, Medtronic introduced the MiniMed, a hybrid closed loop system, after obtaining FDA approval. The hybrid system monitors blood sugars every 5 minutes and directs the pump to either administer or withhold insulin. However, the user must program the pump based on how many carbohydrates are eaten at mealtimes.
There turns out to have been a manufacturing/design defect in the MiniMed pump. The pump has a reservoir, which holds the insulin and which must be changed out every week or so. A retaining ring holds the reservoir in position. There was a problem with the ring; it would break. If it did, it allowed the reservoir to work its way loose. This might result in either no or not enough insulin being delivered or, even worse, too much insulin being delivered. When too much insulin is delivered, especially if this occurs at night when the diabetic is asleep, a profound hypoglycemia can result which can seriously injure or even kill the patient.
After the problem was discovered, Medtronic instituted a recall but some diabetics were injured, purportedly thousands, and there was at least one death related to the defect. Over 300,000 pumps were recalled in a Class 1 recall. This FDA classification is reserved for only the most serious recalls in which there is a risk of serious injury or death. Now the lawsuits are beginning to be filed and law firms are looking for potential clients, who were injured by the defect.
Continued progress in pump technology is important. For reasons that are not clear, more and more young people are being diagnosed with Type 1 diabetes. The advent of a reliable, fully automated, closed loop system will save many lives and make the lives of all Type 1 diabetics easier.