Bubble update - February, 2012
We've been using the 6 mm Quick-Set infusion sets with the Quick-Serter for several years; this is for a Medtronic Paradigm pump. Over a period of a few months recently, there were increasing problems with the infusion sets. The main problem was a rapid increase in blood glucose, not associated with meals or anything else. This generally happened about 2 to 2½ days after the infusion set was inserted. When the infusion set was changed, the blood glucose rapidly returned to the normal range and all was well - at least for another 2 to 2½ days. Also, air bubbles in the tubing continued to be a problem.
We decided to switch from the 6 mm Quick-Sets to 13 mm Silhouette infusion sets, using the Sil-Serter for insertion. What a difference! Essentially no more bubbles, although we still check the tubing for bubbles three times a day. Infusion sets almost always last a full three days. The only problem is increased bleeding around the infusion set, mainly when it's removed. We have no idea why changing the type of infusion set changes the bubble situation, because the bubbles originate in the reservoir. The increased bleeding is probably reasonable. A quick geometry calculation shows that a 13 mm Silhouette cannula inserted at 45° goes in a "perpendicular" distance of 9 mm, compared to 6 mm for the Quick-Sets we used, so there's both a longer penetration and a deeper penetration by the needle and cannula. We've thought about trying the 9 mm Quick-Sets (which wouldn't be as long but would go in as deep as the 13 mm Silhouettes), but haven't bothered so far.
So for people who are having problems with bubbles in their tubing, a possible solution to try is to use Silhouette infusion sets.
