Reduced Silent Occlusions with a Novel Catheter Infusion Set (BD FlowSmart): Results from Two Open-Label Comparative Studies

Abstract

Background: Insulin pump users experience periods of unexplained hyperglycemia. In some cases these may be due to insulin flow interruptions termed “silent occlusions,” which occur without activating the pump alarm and may require set replacement.Materials and Methods: In-line pressure profiles of a novel infusion set with a 6-mm, 28-gauge polymer, dual-ported catheter (BD FlowSmart™; Becton Dickinson and Co., Franklin Lakes, NJ) were compared with those of an existing infusion set (Quick-set®; Medtronic MiniMed, Northridge, CA) in two separate studies involving insulin diluent infusions over 2.5–4.5-h periods in healthy adults without diabetes. Study 1, a pilot study (n = 25), compared the occurrence of flow interruption events (silent occlusions and/or occlusion alarms) between the two infusion sets and between manual or device-assisted insertion methods. Study 2 (n = 60) was designed to show ≥50% reduction in flow interruption events with the BD set after manual insertions. (Silent occlusions were defined by a continuous pressure rise for ≥30 min.)Results: In Study 1, significantly fewer silent occlusions were seen with BD FlowSmart versus Quick-set infusion sets for both manual (three of 22 [13.6%] vs. 12 of 24 [50%]; P = 0.012) and mechanical (two of 24 [8.3%] vs. nine of 25 [36%]; P = 0.037) insertions, yielding risk reductions of 73% (95% confidence interval [CI], 25–91%) and 77% (95% CI, 17–94%), respectively. In Study 2, flow interruption events occurred in three of 117 (2.6%) and 12 of 118 (10.2%) BD FlowSmart and Quick-set infusion sets, respectively, yielding a 75% risk reduction (95% CI, 20–92%; P = 0.030). Percentage of time with flow interruption was significantly lower with BD sets in both studies (P < 0.02). Leakage (>0.5 IU or 5 μL) occurred infrequently and did not differ between sets.Conclusions: A novel side-ported insulin infusion set demonstrated significant reductions in flow interruptions, including silent occlusions, versus a leading marketed set, which may improve insulin delivery.

New Insulin Delivery Recommendations

“…Hirsch 238 reported the occurrence of silent occlusions using insulin diluent in healthy volunteers, in whom pressure measurements were made. Silent occlusion was defined as a continuous rise in pressure of at least 30 minutes without triggering the pump occlusion alarm.…”

ISPAD Clinical Practice Consensus Guidelines 2018: Diabetes technologies

“…Some have explored the use of a small dose of basal insulin, like glargine, to help minimize this complication . Widespread adoption of this has not occurred, and many groups continue to explore how to develop improved infusion sets or fault detection algorithms to advise a user of when insulin delivery may be interrupted …”

Insulin Infusion Set Use: European Perspectives and Recommendations

“…Sources of IIS failure that could result in disrupted insulin delivery are kinking, dislocation or leakage of the cannula, reservoir leakage, a loose connection between the reservoir and cannula, insulin precipitation in the cannula, or occlusions which may or may not trigger pump alarms (see below). 3–5 , 11 In addition, impaired insulin action could result from inflammation at the site of the insertion, blood in the cannula or insertion site, a tissue reaction after a prolonged interval between infusion set changes, or the cannula being placed in unhealthy tissue (e.g., areas of lipohypertrophy).…”