“Toxic Shock:” Can Playground Static Cause Insulin Pump Failure?
Carl R. Baum, MD
Article Outline
To the Editor:
Over the last few decades, a number of manufacturers have developed programmable insulin pumps that allow improved control over insulin delivery via a subcutaneous catheter. The benefits of continuous subcutaneous insulin infusion have been clearly demonstrated in children with Type 1 diabetes.1
Although these pumps have self-testing software and are generally robust, under certain circumstances they may experience disruption of or damage to their electronics. In one published report, a 49-year-old woman visiting a science museum experienced pump failure after indirect contact with the charge from a Van de Graaff electrostatic generator.
2 There are anecdotal reports of children whose pumps malfunctioned after contact with playground slides (J.H. Ahern, personal communication, 2006).
In this case, a 6-year-old girl with Type 1 diabetes noted that her pump (Paradigm 512, software version 2.1D, Medtronic MiniMed, Inc., Northridge, CA) produced unusual sounds and displayed an error code after she slid down her school’s playground slide during an after-school session. Her father arrived within the hour, and discovered that the pump had lost all of its programmable settings, including date, time, and hourly basal insulin infusion rates, and required reprogramming before it could resume normal operation.
The girl recalled that she had slid down the plastic slide head first and in a prone position. Her pump case, held in place with a waist belt, was at the time worn over her clothing, between her abdomen and the slide, with which it made direct contact. It is possible that during the ride down the slide, a static electrical charge accumulated in or around the pump case, and was sufficient to interfere with the pump’s operation.
Dissimilar materials that move relative to one another may produce static electricity; other determinants include ambient weather conditions, particularly lower temperatures and relative humidity. The girl’s clothes were manufactured from cotton, the pump case from ballistic nylon, and the slide from linear low-density polyethylene plastic. The closest station of the National Weather Service, New Haven Tweed Airport (HVN), recorded mild conditions at that hour: temperature, 61°F (16°C), and relative humidity, 67%.3 A call to the MiniMed customer service center (800-MINIMED) revealed that static electricity could cause the pump to display an error code and reset itself to factory settings (ie, no insulin delivery) in order to safeguard against excessive infusion. In addition to notifying the manufacturer of this incident, a report was made to MedWatch, the FDA medical products reporting program.
Patients, parents and other caregivers should be aware that static electricity could interfere with insulin pump operation.
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