An insulin pump infusion set sometimes needs replacement before the insulin cartridge is empty due to mechanical failure or irritation at the insertion site. Changing the entire system would mean discarding a significant amount of perfectly good insulin. The practice of changing only the on-body infusion set while retaining the existing cartridge is a common strategy for individuals using tubed pumps to minimize waste and conserve insulin. This procedure involves separating the tubing from the old set and attaching it to a new one.
Essential Preparation Before the Change
Before beginning the process, a user must assemble all necessary materials to ensure a smooth and sterile transition. Required supplies include a brand-new infusion set, alcohol wipes for site preparation, and potentially medical tape for securing the new site and tubing. Thoroughly washing hands with soap and water is necessary to prevent the introduction of bacteria and avoid infection.
The pump must also be prepared by navigating to the menu and selecting the option to stop or suspend insulin delivery. This action immediately ceases the basal rate to prevent accidental insulin delivery while the tubing is disconnected and reconnected. Users should visually check the cartridge to confirm that a practical amount of insulin remains, justifying the effort of this partial change. If the remaining volume is only a small amount, a complete set and cartridge change might be more efficient.
Detailed Procedure for Tubing Separation and Reconnection
The physical process begins with the careful removal of the failed infusion set from the body. After loosening the adhesive from the skin, the entire old set is pulled away, ensuring the attached tubing remains connected to the pump and the full cartridge. The user must then disconnect the old tubing from the cannula housing of the discarded set. This connection point, often a twist-lock or snap-fit mechanism, is the only piece being replaced.
The existing tubing, still filled with insulin and connected to the cartridge, must be carefully held to avoid stress on the pump connection. The user takes the brand-new infusion set and removes its accompanying new tubing, which is no longer needed. The old tubing is then swiftly connected to the cannula housing of the new infusion set, typically involving a distinct click or firm twist to ensure a secure, leak-proof connection.
Next, the new infusion set is inserted into a prepared, clean, and rotated site on the body, following the manufacturer’s directions, usually with a serter device. The cannula is inserted beneath the skin, and the adhesive is secured to the body before the insertion needle or wire is retracted. The entire assembly now consists of the original cartridge, the original insulin-filled tubing, and a brand-new, on-body cannula and adhesive patch. This process is time-sensitive, as insulin delivery has been suspended, and the site is vulnerable to contamination.
Post-Change Safety Protocol and Monitoring
After the new set is physically secured to the body, the next sequence of actions focuses on safety and ensuring successful insulin delivery. The primary step is priming the new cannula to push insulin from the tubing into the small section of the line beneath the skin. This procedure is typically initiated through the pump’s menu, often labeled as a “Fill Cannula” or “Prime Set” function, and uses a calculated, small dose of insulin, usually between 0.3 and 0.7 units, depending on the cannula length.
This priming step is necessary because the connection point at the new set contains a small volume of air. This air must be purged to prevent an air bubble from blocking insulin flow into the subcutaneous tissue. Air in the line can lead to under-dosing and unexpected high blood glucose levels. Once the priming is complete, the user must resume the basal insulin delivery via the pump menu.
To confirm the new site is absorbing insulin effectively and the cannula is not kinked, a small mealtime bolus should be delivered shortly after the change. Following this bolus, blood glucose monitoring becomes a priority, with checks recommended approximately one to two hours after the site change. A stable or declining blood glucose level confirms proper absorption, while an unexplained rise may indicate a site failure, demanding immediate correction and potentially another infusion set change.