It has been nearly 50 years since insulin pump therapy was introduced for diabetes management and more than two decades since the first continuous glucose monitoring (CGM) system was approved by the FDA. Today, each device continues to play progressively prominent roles in the treatment of diabetes, demonstrating their ability to improve outpatient glycemic outcomes and quality of life for patients. According to an article in Diabetes Care, in 2018 approximately 30 to 40 percent of patients with type 1 diabetes used some type of insulin pump or CGM.
“Many patients with insulin pumps also have a CGM device,” notes Felicia A. Mendelsohn Curanaj, MD, an endocrinologist in the Division of Endocrinology, Diabetes, and Metabolism at NewYork-Presbyterian/
The latest technology in diabetes management is the hybrid closed-loop system. With this system, the CGM can communicate readings to the insulin pump, which then automatically adjusts insulin dose delivery according to an algorithm.
Dr. Felicia Mendelsohn Curanaj
Dr. Tiffany Yeh
Dr. Michele Yeung
Increasingly, patients are wearing these devices when they are hospitalized and, as a result, hospital-based healthcare providers — through collaboration with diabetes experts — should understand how to manage and utilize these devices safely and appropriately. With this in mind, Dr. Mendelsohn, along with endocrinologists Tiffany Yeh, MD, and Michele Yeung, MD, in the Division of Endocrinology, Diabetes, and Metabolism at NewYork-Presbyterian/
“In the past 10 years, insulin pumps have become more popular among patients and we have many more patients who are wearing them when admitted to the hospital,” says Dr. Mendelsohn. “There has also been an increase in popularity of continuous glucose monitors, and, more recently, we have been seeing patients admitted with hybrid closed-loop systems.”
Drs. Mendelsohn, Yeh, and Yeung advise that in any circumstance that may affect the use of continuous glucose insulin infusion and CGM devices while a patient is in the hospital, consultation with an endocrinologist or diabetes specialist is warranted to ensure that the healthcare team can proceed safely with regard to glycemic management.
“With patients used to wearing these devices in the outpatient setting, when they are admitted, they often expect to continue to use them,” says Dr. Yeh. “I think one of the major issues is a disconnect between outpatient and inpatient care. Since patients wear these devices continually, they may not think to let their inpatient team know, especially when their hospital admission is unrelated to their diabetes. At the same time, the inpatient teams may not be familiar with these technologies and how to manage them appropriately.”
Dr. Yeung concurs. “Managing these devices in the setting of radiology studies is another unique aspect that we don’t encounter as frequently in the outpatient world. Hospitalized patients who need imaging tests may be asked to remove their devices. This potentially could be very dangerous in someone with type 1 diabetes who cannot go for prolonged periods of time without insulin. We recognized the importance of educating inpatient providers to recognize these devices on their patients and to involve the endocrine team when appropriate.”
Infusion Pumps for Inpatients: Considerations for Continuing or Suspending
Drs. Yeh, Yeung, and Mendelsohn note that some inpatient care team members may be unfamiliar with continuous subcutaneous insulin infusion and CGM technologies. Therefore, they advise that in any circumstance that may affect the use of these devices while a patient is hospitalized, consultation with an endocrinologist or diabetes specialist is warranted to ensure that the healthcare team can proceed safely with regard to glycemic management.
They add that the ongoing use of patients’ own devices while in the hospital is contingent on a number of factors. These include whether the patient has the physical and mental capacity to safely manage their pump; whether hospital policies support the continued personal use of insulin pumps; and if providers are familiar with the specific diabetes technology.
“When I joined NewYork-Presbyterian/
Dr. Mendelsohn points out there are many reasons insulin pump settings may need to be adjusted during hospitalization, from diet and medication changes to procedures patients will undergo. “Depending on why the patient is in the hospital, they may be eating differently than they do at home. They may not be permitted to eat because they are going to have surgery. An infection may raise their blood glucose levels or the patient may be started on a medication such as prednisone that will also raise their glucose levels. Some imaging studies or prolonged surgeries may require the insulin pump to be removed. The patient may need to be temporarily transitioned to subcutaneous insulin injections or an intravenous insulin infusion, and then transitioned back to their insulin pump after the procedure is completed. For all these reasons and more, we are called in to consult when patients are first admitted and then to follow them throughout their inpatient stay.”
The expert panel that developed the 2020 Continuous Glucose Monitor and Automated Insulin Dosing Systems in the Hospital Consensus Guideline recommends that devices should be discontinued in the hospital for patients with:
- diabetic ketoacidosis,
- rapidly changing glucose levels and fluid/electrolyte shifts,
- skin infections or edema near the sensor site, and
- patients treated with vasoactive agents for poor tissue perfusion
A number of other clinical concerns may preclude continued use or necessitate adjustment to device settings. For example, contraindications may develop because of a patient’s medical condition, such as changes in skin perfusion, blood pressure, or body temperature, which can affect the accuracy of continuous glucose monitoring devices. Renal injury or hepatic failure resulting in uremia may limit the ability of patients to manage the insulin pump. Discontinuation is also advised if patients are in an ICU or critically ill.
Risks for hypoglycemia or hyperglycemia also are important considerations. The risk for hypoglycemia, which is of concern for any patient on insulin therapy, is heightened during hospitalization for those on a continuous subcutaneous insulin infusion pump. Hyperglycemia can develop during inpatient care as a result of treatment with high-dose glucocorticoids, enteral feedings, infections, changes in dietary intake, and stress related to the hospitalization. Both conditions develop more commonly in patients admitted to an ICU.
COVID-19 Expedites the Inpatient Use of CGMs
During the COVID-19 pandemic, interest in the use of CGMs in the hospital setting was intensified. “Because of the pandemic, some hospitals began using CGMs as a way to reduce the need for multiple fingerstick glucose measurements per day, to both conserve personal protective equipment and reduce repeated exposure among healthcare professionals to COVID-19,” notes Dr. Mendelsohn. “In April 2020, the FDA issued temporary allowances known as enforcement discretion for in-hospital use of two CGM devices for patients with COVID-19.”
“In the height of the pandemic, COVID-19 infection appeared to precipitate severe hyperglycemia, so being able to safely monitor these patients became an issue,” says Dr. Yeung. “Checking fingersticks exposed nurses to higher risk of contagion. This combined with the need to conserve PPE, the idea of using CGMs in these patients to provide real-time glucose data became of interest."
The continued use of insulin pumps by patients when they are hospitalized is endorsed by the Endocrine Society, the American Diabetes Association, the American Association of Clinical Endocrinologists, and the Association of Diabetes Care & Education Specialists and supported by several studies. The rationale is an evident one: Continued insulin pump usage during the hospital stay sustains patient independence with diabetes self-care. Patients also prefer to continue with their own systems when in the hospital, which also offers an opportunity for providers to modify settings, if needed.
“One of the key messages for endocrinologists who are not based in a hospital is to advise their patients who are using these technologies that it is important for them to communicate that to an admitting hospital physician and other members of an inpatient healthcare team,” stresses Dr. Mendelsohn.
“Community physicians should let their patients with diabetes know that they will likely be able to stay on their devices,” add Dr. Yeh, “but to make sure their inpatient providers are aware of their condition and that they will need appropriate management for their diabetes while admitted.”