Background Insulin pumps are a frequently used technology among youth with type 1 diabetes. Air bubbles within insulin pump tubing are common, preventing insulin delivery and increasing the risk of large glycemic excursions and diabetic ketoacidosis (DKA). We sought to determine the prevalence of air bubbles in insulin pump tubing and identify factors associated with clinically significant air bubbles. Methods Fifty-three subjects were recruited over 65 office visits. The insulin pump tubing was visualized, and any air bubbles were measured by length. The length of air bubbles was then converted to time without insulin at the lowest basal rate. Generalized linear model (GLM) was used to determine the associations between air bubble size and other variables. Results Of the 65 encounters, 45 had air bubbles in the tubing. Five (5/65 = 7.7%) encounters had a time without insulin of more than 60 min. Air bubble size was inversely correlated with time since infusion set change (p < 0.001), and directly correlated with age of the subject (p = 0.049). Conclusions Significantly more air bubbles were found in the tubing of insulin pumps soon after infusion set change and with older subjects, suggesting a relationship with the technique of filling the insulin cartridge and priming the tubing.
Keywords: insulin pump therapy; pediatric; technology; type 1 diabetes.