Changes in altitude cause unintended insulin delivery from insulin pumps: mechanisms and implications.

ABSTRACT:

Objective

Children and adults with type 1 diabetes who receive insulin pump therapy have reported hypoglycemia during air travel. We studied the effects of atmospheric pressure on insulin pump delivery.

Research design and methods

Ten insulin pumps were connected to capillary tubes. The effects of changes in ambient pressure on insulin delivery, bubble formation, bubble size, and cartridge plunger movement were analyzed.

Results

During a flight (200 mmHg pressure decrease), excess insulin delivery of 0.623% of the cartridge volume occurred (P < 0.001, Student t test). In hypobaric chamber studies, bubbles developed in the insulin when the pressure decreased and displaced the insulin out of the cartridge. Pre-existing bubbles changed in size consistent with Boyle law.

SUBMITTER: King BR 

PROVIDER: S-EPMC3161261 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature