Air Bubbles in the Reservoir and Infusion Line

bubbles in the reservoirAir bubbles in the reservoir are not a problem unless they are large and enter the infusion line, replacing insulin. If air bubbles are seen in the infusion line, an inch of air in the line equals approximately half a unit of insulin. In most cases, up to an inch of air in the line is not a concern but requires visual inspection.

Removing Air Bubbles from the Reservoir

  1. Hold the reservoir properly – Place it in the palm of your hand and point the needle up, ensuring the air bubble moves toward you.
  2. Position the reservoir correctly – Tip the reservoir so the bottom (plunger end) is slightly farther away than the needle end.
  3. Tap the reservoir – Use a fingernail or pen to flick the reservoir until the bubble moves into the neck.
  4. Expel the air – Squirt a small amount of insulin back into the vial to remove the bubble.

Preventing Air Bubbles in the First Place

  • Use room temperature insulin – Cold insulin can create bubbles when warming up inside the reservoir. Let it sit for 15–30 minutes before filling.
  • Tap out bubbles before drawing insulin – Hold the insulin vial upside down and flick it gently to move bubbles to the top before filling the reservoir.
  • Draw insulin slowly – Pulling the plunger too fast can introduce air pockets.
  • Expel air before connecting – Hold the reservoir upright, tap it gently, and push out bubbles before attaching it to the pump.
  • Prime the tubing thoroughly – Hold the tubing vertically during priming to ensure no bubbles remain before connecting to the infusion set.

Removing Air Bubbles from the Tubing

If bubbles are visible in the tubing:

  1. Disconnect from the infusion set.
  2. Hold the tubing vertically, with the pump facing downward.
  3. Prime until all bubbles are expelled.
  4. Reconnect and visually inspect for any remaining bubbles.

Following these steps can minimize the risk of insulin delivery issues caused by bubbles in the reservoir and tubing.


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