DEFINITION

• Goal of inpatient management: achieving a level of glycemic control that will improve patient outcomes, while reducing the risk of either hypoglycemia or iatrogenic diabetic ketoacidosis (DKA).
• In critically ill patients: 2009 AACE/ADA recommendations: intravenous (IV) insulin infusion to control hyperglycemia targeting 140 - 180 mg/dL (target < 110 mg/ dL is no longer recommended) (Moghissi).
• In non-critically ill patients: 2009 AACE/ADA recommendation: premeal target < 140 mg/dL, random BG < 180 mg/ dL; if BG < 100, consider reassessing insulin regimen; if BG < 70, regimen should be modified.

EPIDEMIOLOGY

• Inpatient hyperglycemia is associated with increased infection, impaired healing, increased renal failure, risk of organ failure following transplant, and increased overall mortality.
• Medical conditions that cause glucose instability:infection, renal failure, malnutrition, advanced age, steroids and other medications that impair glucose homeostasis.
• Carbohydrate administration by tube feedings, parenteral nutrition, and intravenous dextrose solutions frequently cause hyperglycemia.
• Disruptions in nutrition are common due to nothing by mouth (NPO) orders, anorexia or feeding intolerance, putting patients at risk for hypoglycemia.

CLINICAL TREATMENT

• There are numerous contraindications to use of oral agents during acute illness (Figure 1).
• The general recommendation is to discontinue oral agents during hospitalization.

• Use IV insulin infusion to control hyperglycemia in critically ill patients, and all patients with DKA or hyperglycemic hyperosmolar state (HHS).
• Consider IV insulin peri-operatively, those destabilized by high dose steroid pulses, or with hyperglycemia non-responsive to subcutaneous (SQ) therapy.
• Administer IV insulin using validated written or computerized protocols that allow for predefined adjustments in the insulin infusion rate based on glycemic fluctuations and insulin dose.

• For non-critically ill patients: Scheduled subcutaneous (SQ) insulin injections are recommended above "sliding scale" correction alone, because of proven efficacy and decreased risk of both hyper and hypoglycemia.
• Physiologic insulin dosing is recommended, including basal, nutritional, and correctional components, based on the concept of "total daily dose (TDD)" of insulin (figures 2 and 3).
• For insulin deficient patients (type 1 diabetes, post total pancreatectomy, or type 2 diabetes treated at home with insulin > 5 years): use basal insulin at all times, even if not receiving nutrition, to prevent ketosis.
• The basal component of insulin is typically 40 - 50% of the TDD of insulin; for patients who are NPO, eating poorly, or have hypoglycemia, consider 20-40% reduction in basal dose.
• Insulin deficient patients, if eating, require nutritional insulin, typically 10 - 20% of the TTD; hold nutritional insulin if the patient is NPO or does not consume at least 50% of their carbohydrates.
• With new onset hyperglycemia, or type 2 diabetes managed with diet or oral agents at home place initially on correctional insulin alone (rapid acting, by sliding scale); however, prolonged therapy with sliding scale insulin alone is not recommended.
• Consider adding basal and/ or nutritional insulin if patient requires > 20 units of correctional insulin per 24 hours, or if hyperglycemia persists despite correction.
• If hyperglycemia continues, total the doses of correctional insulin over the previous 24 hours to gauge the next day's regimen. Add 50% of the correctional total to the current basal dose; add 15% of the correctional total to current mealtime nutritional doses.
• If hypoglycemia occurs, decrease the total daily dose by 20%. Consider switching to a less aggressive correctional scale.

• Patients using insulin pumps at home may have mental status changes that can impede safe self-management of pump due to pain medication, sleep deprivation, medically induced delirium, and severe physiological stress.
• For safe insulin pump therapy during a hospital stay, establish a systematic approach to screening patients for contraindications, clear and detailed guidelines for staff to follow in case of pump failure, and the availability of knowledgeable personnel.
• Institution policies should specifically define safety practices and responsibilities of the patient, nurse, prescriber, and pharmacy.
• Patient self monitoring, insulin administration and documentation is always observed by the nurse and confirmed in the medical record.

• Hospitalization frequently disrupts nutrition in unexpected ways. For example: NPO for unexpected procedures; malfunction of feeding tubes; malfunction of lines delivering parenteral nutrition. For these events, basal/ nutritional/ correctional insulin dosing can increase patient safety.
• Nutritional insulin is scheduled and dosed to maintain euglycemia during absorption of carbohydrates; if the carbohydrate source is disrupted, the nutritional insulin component is held, thereby reducing the risk of hypoglycemia.
• Patients eating meals or on bolus tube feeds: Rapid-acting insulin analogs provide better coverage of absorbed carbohydratethan does regular insulin, improving glycemic controland reducing the risk of insulin "stacking" between breakfast and lunch doses, thereby reducing the risk of mid-afternoon hypoglycemia. See figure 4.
• NPO status: If a patient is made NPO, consider basal insulin dose reduction (e.g. 20 - 40%); holdnutritional insulin; continue correctional insulin.
• Continuous tube feeds: The glycemic response to continuous enteral nutrition is exaggerated compared to that of discrete meals; nutritional insulin can be provided as a fixed dose of short or rapid acting insulin every4-6 hours to reach glycemic targets, and allow the insulin tobe held if the tube feed is disrupted, reducing the risk of hypoglycemia. Insulin deficient patients will also continue to receive SQ basal insulin and correctional insulin (Gottschlich).
• Parenteral nutrition:The glycemic response to parenteral nutrition is exaggerated compared to discrete meals. Insulin can be added to the parenteral nutrition formulation, delivering nutritional insulin in concert with incoming carbohydrates. If the parenteral source is disrupted, nutritional insulin automatically stops, reducing the risk of hypoglycemia. Insulin deficient patients will also continue to receive SQ basal insulin and correctional insulin (Gottschlich).
• Cycled nutrition regimens (enteral or parenteral) are highly individualized, and will benefit from the expertise of endocrinology or specialists in parenteral/enteral support.

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