Infusion pumps, insulin

Insulin pump therapy consists of a programmable infusion device that allows for basal infusion of insulin 24 hours daily, as well as bolus administration following meals. As seen in Fig. 40-3, an insulin pump consists of a programmable infusion device with an insulin reservoir. This pump is attached to an infusion set with a small needle that is inserted in subcutaneous tissue in the patient s abdomen, thigh, or arm. Most patients prefer insertion in abdominal tissue because this site provides optimal insulin absorption. Patients should avoid insertion sites along belt lines or in other areas where clothing may cause undue irritation. Infusion sets should be changed every 2 to 3 days to reduce the possibility of infection. 

Although infusion pumps can go some way towards mimicking normal control of blood insulin levels, transplantation of insulin-producing pancreatic cells should effectively cure the diabetic patient, and research aimed at underpinning this approach continues. 

INSULIN GLULISINE Give within 15 minutes before a meal or within 20 minutes after starting a meal. Insulin glulisine is intended for subcutaneous administration and for use by external infusion pump. 

Insulin aspart If insulin aspart is mixed with NPH human insulin, draw insulin aspart into the syringe first. Do not mix insulin aspart with crystalline zinc insulin preparations. When used in external subcutaneous infusion pumps for insulin, do not mix with any other insulins or diluent. 

II.f.1.3. Insulin delivery. Traditionally insulin was given intramuscularly and later subcutaneously. New technology has provided devices for insulin administrations including pen-devices, air powered injectors, external insulin infusion pumps (or continuous subcutaneous insulin infusion, CSII), and implantable insulin infusion pumps. Some novel forms of insulin delivery have been introduced, for example intranasal insulin gives peak insulin concentrations at 10-20 minutes after administration, but most insulin is still administered subcutaneously. 

The standard mode of insulin therapy has traditionally been by subcutaneous injection using disposable needles/syringes. However, other routes of administration, including continuous subcutaneous insulin infusion pumps and inhalation of finely powdered aerosolized insulin, are currently being explored. 

Controlled-rate infusion devices, as well as feedback-regulated drug delivery devices, have the potential to improve drug safety and efficacy. With advancement in computer technology and miniaturization of precision motors, highly compact computer-controlled infusion pumps are now available for insulin delivery. These pumps, weighing about 3 to 4 ounces, can be... 

Insulin, human recombinant, yeast (i cerevisiae), infusion pump or syringe refills... 

In 132 patients with type 2 diabetes using insulin randomly assigned to continuous subcutaneous insulin infusion (with insulin aspart) or multiple daily injections of insulin aspart and NPH insulin) for 16 weeks, after 8 weeks training to establish optimal dosages (191) there were more episodes of hyperglycemia (blood glucose over 19.4 mmol/1) with multiple daily injections. HbAic was identical. Most of the patients who expressed a view (93%) wanted to stay on the pump. 

Implantable insulin infusion pumps have been reviewed (232,233), as has the use of pumps in children (234). In 31 centers, 914 pumps were implanted, representing 2121 patient-years. Some commonly reported pump complications were (233) ... 

Sola-Gazagnes A, Pecquet C, Radermecker R, Pietri L, Elgrably F, Slama G, Selam J-L. Successful treatment of insulin allergy in a type 1 diabetic patient by means of constant subcutaneous pump infusion of insulin. Diabetes Care 2003 26 2961-2. 

Human insulin from E coli is available for clinical use as Humulin (Lilly) and dispensed as either regular, NPH, lente, or ultralente Humulin. Human insulin prepared biosynthetically in yeast is marketed by Novo Nordisk as human insulin injection in regular, lente, and NPH forms Novolin R, Monotard Human Insulin (Novolin L), and Novolin N. The same company also produces a human insulin marketed as Velosulin (regular) that contains a phosphate buffer. This reduces aggregation of regular insulin molecules when used in infusion pumps. However, because of the tendency of phosphate to precipitate zinc ions, Velosulin should not be mixed with any of the lente insulins. 

In drug delivery, infusion pumps have achieved remarkable success in recent years. As of 1983, there were 18 different models of external pumps available (6). These battery-powered portable pumps are used to infuse insulin into diabetic patients. Although capable of variable delivery rates, they have a reservoir volume of less than 6 ml, which is unsuitable for fluid replenishment. Further, the cost of these small pumps is very high which limits the affordability to a few selected individuals. 

Data on Insulin Infusion Pumps per Sept. 1983", compiled and published by Novo Industri A/S, Denmark. 

The JCAHO has a major focus on patient safety, including medication safety. As facilities report internal sentinel events to JCAHO, they are reviewed and analyzed. JCAHO has issued a number of sentinel event alerts, notifying healfh care organizafions and consumers to specific safety issues and practice recommendations to improve them. Several have addressed medication issues such as potassium chloride and other concentrated electrolytes, insulin, heparin, injectable opiates and narcotics, infusion pumps, and look- and sound-alike medications and abbreviations. Table 16.10 summarizes the recommendations for these sentinel event alerts. ... 

This difference may have clinical importance and this is why some continous infusion pumps (see below) deliver insulin intraperitoneally rather than subcutaneously. 

In addition to needles and syo inges, alternative techniques for insulin administration have been developed, some availing themselves of the kinetics of insulin insulin pens (supplied preloaded or with replaceable cartridges), external infusions and implantable pumps. These latter are convenient for cm accurately controlled continuously functioning biofeedback system, but pose difficulties for routine replacement in insulin deficiency. Therefore sustained-release (depot) formulations are used to provide an approach reasonably near to natural function and compatible with the convenience of daily living. An even closer approach is provided by the development of (at present inevitably expensive) miniaturised infusion pumps which can be used by reliable patients. 

Use of a slow-infusion pump with a concentrated solution (insulin 1.0 unit/ml) is recommended. Insulin loss is minimised and control of dose is more accurate than when more dilute solutions are used. (For i.v. doses see diabetic ketoacidosis, below.) Insulin is suitable for adimistration by continuous i.v. infusion because its short t/ (5 min) means that the plasma concentration rapidly reaches steady state after initiating the infusion or altering its rate (5 X see p. 101). Long-acting (sustained-release) preparations must not be given i.v. 

A typical example is the development of Infusaid , an implantable infusion pump by Metal Bellows, for the constant infusion of heparin in anticoagulation treatment,of insulin in the normoglycermic control of diabetics,and of morphine for patients suffering from the intensive pain of a terminal cancer. ... 

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