Insulin therapy infusion

Currently, the most advanced form of insulin therapy is the insulin pump, also referred to as continuous subcutaneous insulin infusion (CSII). Using the short- or rapid-acting insulins only, these pumps are programmed to provide a slow release of small amounts of insulin as the basal portion of therapy, and then larger bolus doses are injected by the patient to account for the consumption of food. 

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. 

Kamoi K, Miyakoshi M, Maruyama R. A quality-of-life assessment of intensive insulin therapy using insulin lispro switched from short-acting insulin and measured by an ITR-QOL questionnaire a prospective comparison of multiple daily insulin injections and continuous insulin infusion. Diabetes Res Clin Pract 2004 64 19-25. 

Buysschaert et al. (1983) reported a better glycaemic control of totally insulin-dependent diabetic patients under continuous insulin infusion compared with conventional insulin therapy (Lager et al., 1983). An improved metabolic control, an increased glucose-disposal rate and an inverse insulin resistance following a more physiological insulin regimen with continuous insulin infusion compared with conventional therapy was also reported (Jarret, 1986). Similar results were observed by Muhlhauser et al. (1987) where an intensified insulin injection therapy performed as routine treatment of Type-1 diabetics significantly lowered HBA) levels (Fig. 13). 

An improved metabolic control with intensified insulin therapy compared with a conventional treatment was reported by Wolf et al. (1987). A continuous insulin infusion with insulin pump therapy, monitored over 1 year, however, did not exhibit a clear advantage. The management of even preschool children with insulin pump therapy was not associated with an increased frequency or an accelerated rate of development of ketosis (Flores et al., 1984 Brambilla et al., 1987). However, Marshall et al. (1987) reported more abscesses and ketoacidosis in children on CS1I, and an increased risk of developing cutaneous infections was also noted in patients treated by CSII in the Oslo Study (Dahl-Jorgensen et al., 1985). 

Macrovascular Complications. The connection between high insulin levels (hyperinsulinemia), insulin resistance, and cardiovascular events incorrectly leads some clinicians to believe that insulin therapy may cause macrovascular complications. The UKPDS and DCCT found no differences in macrovascular outcomes with intensive insulin therapy. One study, the Diabetes Mellitus, Insulin Glucose Infusion in Acute Myocardial Infarction study " reported reductions in mortality with insulin therapy. This group assessed the effect of an insulin-glucose infusion in type 2 DM patients who had experienced an acute myocardial infarction. Those randomized to insulin infusion followed by intensive insulin therapy lowered their absolute mortality risk by 11% over a mean follow-up period of approximately 3 years. This was most evident in subjects who were insulin-naive or had a low cardiovascular risk prior to the acute myocardial infarction. " ... 

Which type of insulin is commonly used for insulin therapy in patients who wear external SC insulin infusion pumps ... 

CONTINUOUS SUBCUTANEOUS INSULIN INFUSION A number of pumps are available for continuous subcutaneous insulin infusion (CSII) therapy. CSII, or pump, therapy is not suitable for all patients because it demands considerable attention, especially during the initial phases of treatment. For patients interested in intensive insulin therapy, a pump may be an attractive alternative to several daily injections. Most pumps provide a constant basal infusion of insulin and have the option of different infusion rates during the day and night to help avoid the dawn phenomenon and bolus injections that are programmed according to the size and nature of a meal. 

Metabolism Hypoglycemia When 97 patients mean age 53 years with severe brain injury were randomized to an insulin infusion when their blood glucose concentrations exceeded 12 mmol/1 or to maintain blood glucose concentrations between 4.4 and 6.7 mmol/1, those who received more intensive insulin therapy not surprisingly... 

Bruttomesso D, Costa S, Bariussio A. Continuous subcutaneous insulin infusion (CSII) 30 years later still the best option for insulin therapy. Diabetes Metab Res Rev 2009 25 99-111. 

Fatourechi MM, Kudva YC, Murad H, Elamin MB, Tabini CC, Montori VM. Hypoglycemia with intensive insulin therapy a systematic review and metaanalyses of randomized trials of continuous subcutaneous insulin infusion versus multiple daily injections. J Clin Endocrinol Metab 2009 94 729. ... 

Lactic acidosis is associated with high mortality (66). The treatment of lactic acidosis consists of massive bicarbonate infusions with early administration of frusemide or dialysis. Infusion of too much concentrated bicarbonate may lead to hyperosmo-larity (68). Insulin therapy is also important, as many patients have unexpected ketoacidosis (68, 75). Corticoids, vasopressors or methylene blue do not modify the course of lactic acidosis (68). 

Garg R, Chaudhuri A, Munschauer F, Dandona P. H3fperglycemia, insulin, and acute ischemic stroke a mechanistic justification for a trial of insulin infusion therapy. Stroke 2006 37 267-273. 

Dextrose and insulin (with or without sodium bicarbonate) are typically given at the time of calcium therapy in order to redistribute potassium into the intracellular space. Dextrose 50% (25 g in 50 mL) can be given by slow IV push over 5 minutes or dextrose 10% with 20 units of regular insulin can be given by continuous TV infusion over 1 to 2 hours. The onset of action for this combination is 30 minutes and the duration of clinical effects... 

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. 

When preparing an insulin infusion for a patient, several factors must be considered. Insulin will absorb to glass and plastic, reducing the amount of insulin actually delivered by 20% to 30%. Priming the tubing will decrease variability of insulin infused. Therefore, when patients can be converted safely from infusion to needle and syringe therapy, the total daily dose should be reduced by 20% to 50% of the daily infusion amount. 

The patient was admitted to the hospital with a presumptive diagnosis of health care-associated pneumonia (based on the recent hospitalization). He received intravenous hydration with normal saline, 5 L oxygen via face mask, an insulin infusion to control his glucose, and empirical antimicrobial therapy with piperacillin-tazobactam 2.25 g intravenously every 6 hours and vancomycin 1 g intravenously every 24 hours. All other medications are continued with the exception of the diabetes medications. 

For persons with type 1 diabetes, insulin replacement therapy is necessary to sustain life. Pharmacologic insulin is administered by injection into the subcutaneous tissue using a manual injection device or an insulin pump that continuously infuses insulin under the skin. Interruption of the insulin replacement therapy can be life-threatening and can result in diabetic ketoacidosis or death. Diabetic ketoacidosis is caused by insufficient or absent insulin and results from excess release of fatty acids and subsequent formation of toxic levels of ketoacids. 

In 1500 patients in intensive care, there was hypoglycemia (4 mmol/1 and less) in 5.2% of the intensively treated group and 0.8% of those who received conventional therapy (93). It has been reported that 11% of drug errors are from insulin administration errors and it has been recommended that frequent checks be made of infusion systems (93). 

Insulin delivery by a pump may be superior to glargine insulin. Continuous subcutaneous insulin infusion was compared with intensive therapy with insulin glargine plus insulin lispro in 19 patients (224). The patients who received insulin glargine were exposed to glucose concentrations under 3.9 mmol/1 overnight for three times as long as those who used continuous subcutaneous insulin infusion. 

Catheter malfunction was the most frequent event (obstruction, total occlusion, and peritoneal adhesions 13,10, and 3.1 events per 100 patient-years respectively). Flushing sometimes prevented occlusion. Better tip design had a big effect. Adhesion formation decreased with daily injections of heparin. The frequency of ketoacidosis was comparable to that reported with continuous subcutaneous insulin infusion and was usually related to catheter obstruction. It diminished during the review period. Episodes of severe hypoglycemia were fewer than during intensive subcutaneous therapy. 

---