Unintended Insulin Pump Delivery in Hyperbaric Conditions

Area of Science:

• Biomedical Engineering
• Endocrinology
• Medical Devices

Background:

• Previous insulin pump models showed unintended insulin delivery due to decreased atmospheric pressure, linked to air bubbles.
• This phenomenon explained hypoglycemia in patients after flight takeoff.
• New waterproof insulin pumps are available, but their performance under pressure changes remains unclear.

Purpose of the Study:

• To investigate if new insulin pump models exhibit variations in insulin delivery under hyperbaric conditions.
• To assess the impact of atmospheric pressure changes on insulin pump function in simulated diving environments.

Main Methods:

• Three new insulin pump models were tested.
• Pumps were subjected to hyperbaric conditions simulating increased atmospheric pressure.
• Testing was conducted at a standard flow rate of 2 U/h.

Main Results:

• Atmospheric pressure variations significantly affected insulin release from the pumps.
• Increased pressure (1 to 1.3 ATA) led to decreased basal insulin release (-0.2 U/10 min).
• Decreased pressure (1.3 to 1 ATA) resulted in unintended insulin delivery (+0.3 U/10 min), independent of pump rate but dependent on air bubbles.

Conclusions:

• New insulin pumps are susceptible to unintended insulin delivery under hyperbaric conditions.
• Patients using insulin pumps should be aware of potential insulin delivery variations during flights and diving.
• Monitoring insulin rates is crucial for patients during activities involving atmospheric pressure changes.