Insulin pump complications among children with diabetes

Insulin pump–associated adverse events

Insulin pump–associated adverse events can be broadly defined to include “any untoward medical occurrence in a patient using an insulin pump, specifically those directly stemming from the pump intervention and its use, as opposed to the diabetes itself.”⁵ These can range from mild events that patients can comfortably resolve at home to severe events that require hospitalization. Studies with various cohorts of children found that all reported adverse events ranged from 0.5 to 5 per person-year and rarely required hospitalization.^6-10 This variability can be attributed to differences in study participant demographic characteristics and in thresholds of adverse event reporting used in participant recruitment protocols. Studies have not found associations between adverse events and sex, diabetes duration, glycemic control, or socioeconomic status.^8,9 Adverse events include technical faults, skin-related complications, and metabolic adverse events.

Technical faults usually result in the pump no longer delivering insulin and include hardware failure, battery failure, and software failure. Technical faults can be caused by excessive water exposure, improper use, damage from being dropped, sports-related damage, or damage from unknown causes.¹¹ Faults either are troubleshot at home, where patients are often notified via error or alert messages, or require pump replacement. Other technical issues occur at the catheter or infusion site and interrupt insulin delivery, such as catheter occlusion, dislodged cannulas, insulin leakage, air bubbles in the tubing, and tube kinks.⁵ Catheter events rarely lead to complications requiring hospitalization, as patients are educated on how to change infusion sets to address warning messages.^2,12

Skin-related adverse events include scarring, erythema, nodules, lipohypertrophy, and infections.¹³ In a prospective study from Italy with 1046 children and adolescents, 0.3 infection events were reported per person-year, with cellulitis being the most common.¹⁰ These events may disrupt insulin absorption and more research is needed to understand and prevent their interference.⁵

Metabolic adverse events occur when there are interruptions in insulin delivery, leading to hospitalization. Events include diabetic ketoacidosis (DKA) and hypoglycemia. Diabetic ketoacidosis occurs when insulin delivery interruption is not addressed, either because the pump software fails to provide a warning or because an insulin correction bolus is not delivered. Hypoglycemia occurs due to incorrectly timed changing of infusion sets or incorrectly administered insulin boluses, leading to excess insulin.⁸ In a 2006 literature review, 2.7 to 9 episodes of DKA per 100 participants per year were reported in youth,¹⁴ but more recent studies have shown a lower rate, likely due to improved DKA prevention guidelines.² Wheeler et al recorded 3 severe hypoglycemic events requiring hospitalization during a 16-week prospective period in a hospital serving approximately 850 children with type 1 diabetes in Australia.⁸ In a retrospective review of 1 year of data, Rabbone et al from Italy found 1 severe hypoglycemic episode (0.3 episodes per 100 participants per year) and 7 episodes of DKA (2.1 episodes per 100 participants per year) in 11,311 children with type 1 diabetes.⁷ Overall, DKA and hypoglycemia are now uncommon with CSII therapy, but they still present as challenging medical events for children and their families.^7,8

Overall, young children had a higher incidence of air bubble interference, unexplained hyperglycemia, lipohypertrophy, bleeding, and tube kinking, whereas adolescents had a higher incidence of dislodged infusion sets, tunneling (due to their larger muscle mass), and pump blockages.¹⁰

Prevention

Primary care providers have an important role to play in maintaining patients’ confidence in operating their infusion pumps, as well as in providing support for delivery of insulin in the event of pump failure.

Patients who report a lack of trust in infusion pump technology or in their own abilities have a higher incidence of impaired metabolic control due to pump failure.¹⁵ In the event of permanent pump failure, observational studies have found that it takes an average of about 2 days for patients to be able to replace their pumps,^6,8 requiring the use of injections with both short-acting and long-acting insulin to bridge the gap. Educating patients about what to do in the event of insulin pump failure and developing insulin pump discontinuation plans are important education components required with initiation of CSII therapy. Qualitative studies with families of young patients using CSII therapy suggest that primary care providers may revisit these concepts, in addition to the education provided as part of diabetes care, to increase confidence and decrease anxiety in CSII management.¹⁶ Families have reported that increased confidence in self-managing pump failure and awareness of danger signs would reduce hospital admissions or emergency department visits.⁶