II. Epidemiology
- Insulin Pump used by more than half of Type I Diabetics
III. Background
- Device that delivers Insulin subcutaneously
- Most patients use a rapid-acting Bolus Insulin (e.g. Lispro or Humalog) in Insulin reservoir
- Device can deliver Insulin basal rates down to 0.01 units/h
- Costs
- Pumps typically cost $4000 to $6000 with a monthly cost of $300 to $500 for supplies (2022)
- Type II diabetics may have more out of pocket expenses (non-reimbursed costs) than type 1 diabetics
IV. Indications
- Type I or Type II Diabetes Mellitus on multiple Insulin injections per day AND
- Capable and willing to manage the complexities of Insulin Pumps and related activities (e.g. carb counting)
V. Components
- Insulin Pump
- Insulin reservoir (disposable)
- Filled with U-100 (100 U/ml) Bolus Insulin (highly concentrated)
- Bolus Insulin used is typically InsulinLispro (Humalog) or InsulinAspart (Novolog)
- Bolus Insulin is infused at a slow basal rate plus meal time bolus doses
- Control pad
- Pager-sized hand-held computer with small screen
- Enter Insulin Infusion maintenance rate (basal rate)
- Enter bolus dose directly or calculated based on Carbohydrate intake
- Insulin reservoir (disposable)
- Infusion set (disposable)
- Tubing
- Connects Insulin Pump to subcutaneous insertion site
- May be disconnected when showering, bathing, swimming
- Cannula to insert subcutaneously
- Introduced in similar fashion to IV start (except subcutaneous)
- Needle is used to introduce the catheter subcutaneously
- Needle is removed after insertion and catheter is left in place
- Variations
- Omnipod
- Wireless Insulin reservoir attached directly to body at subcutaneous insertion site
- No tubing is required
- Controlled by a wireless device
- Omnipod
- Tubing
- Insertion site
- Subcutaneous cannula with adhesive to hold it in place
- Changed every 3 days (up to 5 days)
- Rotate infusion sites to avoid infection, Lipodystrophy
- In rare cases, site may become infected
- Additional functions
- Some pumps allow for Continuous Glucose Monitoring
- Some pumps are waterproof (others, such as Tandem, must be removed for bathing or swimming)
- Pumps function continuously (providing Basal insulin) and pausing pump (without detaching) is more complicated
- Other related, but separate components
- Continuous Glucose Monitor (CGM)
- Some CGMs integrate with Insulin Pump to function as a "Closed loop system"
- Alternatively, without a CGM, patients should check Blood Glucose at least four times daily
- Continuous Glucose Monitor (CGM)
VI. Protocol: Pump Malfunction
- Typically results in Hyperglycemia (not Hypoglycemia)
- Examples
- Pump failure
- Tube disconnected
- Infusion set leak
- "Insulin Bad"
- Subcutaneous insertion site problem (e.g. insertion at scarred tissue)
- Prevention
- Have emergency supply of backup Insulin and syringes in case of pump failure
- Patients should keep a copy of their current pump settings
VII. Protocol: Persistent Hyperglycemia
- Attempt to use pump to deliver Insulin boluses
- Tests if the Insulin Pump (and infusion set) is functional
- Persistently high Blood Glucose values
- Subcutaneous Insulin injections can still be given in addition to pump
- Detach the pump in severe hyperglycemia Critical Illness or Diabetic Ketoacidosis
- Manage per Insulin Drip or Hourly Subcutaneous Insulin protocols
VIII. Protocol: Hypoglycemia
- See Hypoglycemia Management in Diabetes Mellitus
- Immediately detach pump in severe hypoglycemic episode
- Causes
- Patient error (too high of Insulin dose selected)
- Acute illness (e.g. Acute Kidney Injury, infection)
IX. Procotol: Hospitalization
- Consult endocrinology as needed
- Leave Insulin Pump attached in most cases to provide Insulin basal rate in the hospital setting
- Risk of DKA while detached (patient has no sustained Basal insulin activity, e.g. Insulin Glargine)
- Detach the Insulin Pump during hospitalizations where Insulin will be managed by nursing and provider orders
- Initiate subcutaneous or intravenous Insulin within 30 minutes of discontinuing Insulin Pump
- Indications to detach Insulin Pump
- Insulin Pump malfunction (or supplies unavailable)
- Critical Illness
- Poor Glucose control
- Altered Mental Status
- MRI
X. Adverse Effects
- Lipodistrophy
- Cannula site pain
XI. Safety
-
Diabetic Ketoacidosis is NOT more common with Insulin Pumps (per T1D registry)
- Theoretic risk of unrecognized pump failure did not occur significantly in reality
XII. Resources
- American Diabetes Association
- Wikipedia
XIII. References
- (2022) Presc Lett 29(5): 27-8
- Claudius and Pedigo (2021) EM:Rap 21(8): 10-12
- Smith (2018) Am Fam Physician 98(3): 154-62 [PubMed]