When the Machine Keeping You Alive Fails: An Insulin Pump Horror Story

A type 1 diabetic recounts her Tandem t:slim X2 insulin pump repeatedly failing during a week-long trip to Santa Fe, throwing recurring ‘Cartridge Alarm 20A’ errors that halted insulin delivery. After 25 years on pumps without a single hardware failure, she had no backup long-acting insulin pen and didn’t even know how to use one — a planning gap she traces to never having needed one before. Each false alarm forced her to swap cartridges and waste roughly 40 units of insulin per swap, compounded by the pump’s mandatory 10-unit priming dose on every restart.

The piece is less a product review than a meditation on the asymmetric power dynamic between patients and the device makers they depend on for survival. The author argues that a ‘neutral, positive relationship’ with life-sustaining tech is impossible: every glitch becomes an indignity, and every design decision a hostile act, because the patient bears all the risk while the manufacturer faces none. She eventually learned to ignore the alarms and reuse cartridges — explicitly off-label behavior — to ration supplies until she got home.

The story illustrates a broader reliability and UX problem in FDA-regulated medical devices: closed ecosystems, expensive consumables, brittle failure modes, and forced hardware migrations (her Dexcom 6 CGM is being discontinued, pushing her to the Dexcom 7) leave patients with little recourse when the device misbehaves in the field.