Addition of Insulin to Parenteral Nutrition for Control of Hyperglycemia

Abstract

Administration of parenteral nutrition (PN) may result in hyperglycemia in patients with preexisting diabetes or disease-related insulin resistance, and it can be associated with increased rates of complications. Treatment requires insulin therapy. Insulin can be administered subcutaneously, intravenously via a variable rate sliding scale, or by adding it directly to the PN. The last method is a potentially attractive technique for a number of reasons-it could deliver the insulin intravenously at a steady rate alongside carbohydrates, and in malnourished patients with little subcutaneous tissue, it may prevent the need for frequent insulin injections. Despite such potential advantages, the addition of insulin to PN remains controversial, largely with respect to the bioavailability of insulin in PN and resultant concerns of the risk of hypoglycemia. There is a paucity of long-term quality controlled studies to address this question. The available literature suggests that, at least in the short term, insulin addition to PN can achieve reasonable glycemic control with low rates of hypoglycemia, and the technique compares favorably with the use of long-acting insulin preparations. This literature review finds a wide range of values reported for insulin availability via PN, ranging from 44% to 95% depending on the type of PN container material used and the presence of added vitamins and trace elements. Few studies looking at glycemic control among patients receiving home PN were found, and larger prospective trials are needed to assess the efficacy and safety of this technique in this patient group.

Glycemic Control in Adult Surgical Patients Receiving Regular Insulin Added to Parenteral Nutrition vs Insulin Glargine: A Retrospective Chart Review

“…ASPEN clinical guidelines recommend a target blood glucose (BG) goal of 140–180 mg/dL for adult hospitalized patients receiving nutrition support . Treatment of PN‐induced hyperglycemia requires insulin therapy, and there are many effective routes of insulin administration, including intravenous continuous insulin, subcutaneous long‐acting insulin, subcutaneous short‐acting correctional and/or nutritional insulin, the addition of regular insulin to the PN mixture (RI‐in‐PN), or any combination of these approaches . Sliding‐scale insulin is frequently used alone because of the fear of hypoglycemia in individuals receiving PN, further complicating the management of hyperglycemia .…”

“…A dosing strategy of 1 unit of regular insulin per 10 g of dextrose at the start of PN with a daily titration of 0.5 unit per 10 g of dextrose has been shown effective for patients with DM or hyperglycemia on PN . The use of RI‐in‐PN still remains controversial because of concerns for the bioavailability of regular insulin in PN and the risk of hypoglycemia …”

“…2 Treatment of PN-induced hyperglycemia requires insulin therapy, and there are many effective routes of insulin administration, including intravenous continuous insulin, subcutaneous long-acting insulin, subcutaneous short-acting correctional and/or nutritional insulin, the addition of regular insulin to the PN mixture (RI-in-PN), or any combination of these approaches. 3,5,[8][9][10] Sliding-scale insulin is frequently used alone because of the fear of hypoglycemia in individuals receiving PN, further complicating the management of hyperglycemia. 11 Unfortunately, clinical guidelines do not specify which route or type of insulin optimal, and the current literature is limited.…”

“…The few available studies suggest that RI-in-PN is comparable to insulin glargine in the management of hyperglycemia and incidence of hypoglycemia in individuals receiving PN. 5 Long-acting insulin such as glargine may be favorable because of its predictable absorption through the subcutaneous tissue and lack of pronounced peaks in blood insulin concentrations. 12 However, because of its long duration of action, insulin glargine may carry the risk of hypoglycemia in the event PN is suddenly discontinued or cycled.…”

Addition of Insulin to Parenteral Nutrition Is Not Universally Safe

“…McCulloch et al's review states that the availability of insulin is increased by multivitamin and trace element contents. This was demonstrated in 1977 and confirmed again more recently (4.5% vs 96%) .…”