TECHNICAL FIELD

The present invention relates to medical devices. More specifically, the invention relates to infusion systems with concurrent total parenteral nutrition (TPN)/insulin infusion.

BACKGROUND OF THE INVENTION

Infusion pumps are medical devices that deliver fluids, including nutrients and medications such as antibiotics, chemotherapy drugs, and pain relievers, into a patient's body in controlled amounts. Many types of pumps, including large volume, patient-controlled analgesia (PCA), elastomeric, syringe, enteral, and insulin pumps, are used worldwide in healthcare facilities such as hospitals, and in the home. Clinicians and patients rely on pumps for safe and accurate administration of fluids and medications.

Total parenteral nutrition (TPN) is used to feed a person intravenously when the gastrointestinal tract is nonfunctional or impaired, so that nutrition cannot be provided to the patient through eating. TPN solution can include sugar, carbohydrates, proteins, lipids, electrolytes, trace elements, and various combinations thereof, as required for a particular patient.

Unfortunately, hyperglycemia is one complication associated with administration of TPN. Recent studies have highlighted that hyperglycemia is associated with increased risk of cardiac complications, infection, systemic sepsis, acute renal failure, and death for patients receiving TPN. Glycemic control in these patients is crucial in maintenance of tolerable blood glucose levels, a fact further substantiated by correlated adverse outcomes.

In present practice, TPN solution administration is tapered to 50% of the required dosing for the patient to minimize hyperglycemia and avoid glucose shock. Insulin is premixed in the same IV bag or container with the TPN solution based on calculated requirements for the patient, adding to clinician time and risk of error. Insulin dosing also requires modulation based on monitored glucose levels during infusion. Subcutaneous insulin infusions can be administered to compensate for advancing hyperglycemia. For hypoglycemic situations, increased TPN (and specifically dextrose) delivery is indicated. Thus, infusion of both TPN and insulin as presently practiced is complex and time consuming.

It would be desirable to have an infusion system with concurrent TPN/insulin infusion that would overcome the above disadvantages.

SUMMARY OF THE INVENTION

One aspect of the present invention provides an infusion system for a patient for use with a TPN source of TPN solution and separate insulin source of insulin solution to provide concurrent TPN/insulin infusion, the infusion system including: a fluid administration set having a primary line in fluid communication with the TPN source, a secondary line in fluid communication with the insulin source, and a common outlet line in fluid communication with the primary line, the secondary line, and the patient; a pump operable to removably receive the fluid administration set, the pump being operable to concurrently move the TPN solution through the primary line in response to a TPN solution flow rate signal and the insulin solution through the secondary line in response to an insulin solution flow rate signal; and a flow controller operable to provide the TPN solution flow rate signal and the insulin solution flow rate signal to the pump. The flow controller is further operable to vary the TPN solution flow rate signal and the insulin solution flow rate signal to vary a ratio of TPN solution to insulin solution provided to the patient from the common outlet line.

Another aspect of the present invention provides a method to concurrently deliver a TPN solution from a TPN source and an insulin solution from separate insulin source, the method including: providing a fluid administration set having a primary line, a secondary line, a common outlet line, and a pumping/mixing chamber between and in fluid communication with the primary line, the secondary line, and common outlet line; connecting the primary line to the TPN source; connecting the secondary line to the insulin source; allowing TPN fluid into the pumping/mixing chamber; allowing insulin solution into the pumping/mixing chamber; mixing the TPN solution and the insulin solution to generate an infusion mixture before the common outlet; with a positive displacement pump, driving the TPN solution through the common outlet line at a TPN dose rate and with a positive displacement pump, driving the insulin solution through the common outlet line at an insulin dose rate; and varying at least one of the TPN dose rate and the insulin dose rate to vary a ratio of TPN solution to insulin solution in the infusion mixture.

The foregoing and other features and advantages of the invention will become further apparent from the following detailed description of the presently preferred embodiments, read in conjunction with the accompanying drawings. The detailed description and drawings are merely illustrative of the invention rather than limiting, the scope of the invention being defined by the appended claims and equivalents thereof.

