31. Woodcock TE, Cook TM, Gupta KJ, Hartle A, for the Association of Anaesthetists of Great Britain and Ireland. Guidelines: arterial line blood sampling: preventing hypoglycaemic brain injury 2014. Anaethesia 2014;69:380–385
32. Cembrowski GS, Tran DV, Slater-Maclean L, Chin D, Gibney RTN, Jacka M. Could susceptibility to low hematocrit interference have compromised the results of the NICE-SUGAR trial? Clin Chem 2010;56:1193–1195
33. Hellman R. Interfering factors in quality of glucose management: technological advances in the treatment of type 1 diabetes. In Frontiers in Diabetes. Vol. 24. Bruttomesso D, Grassi G, Eds. Basel, Karger, 2015, p. 63–80
34. Kahneman, Daniel. Thinking, fast and slow. New York, Farrar, Straus and Giroux, 2011
35. Graber ML, Franklin N, Gordon R. Diagnostic error in internal medicine. Arch Intern Med 2005;165:1493–1499
36. Lovig KO, Horwitz L, Lipska K, Kosiborod M, Krumholz HM, Inzucchi SE. Discontinuation of antihyperglycemic therapy after AMI: medical necessity or medical error? Jt Comm J Qual Patient Saf 2012;38(9):403-407
37. Leape LL, Berwick DM, Bates DW. What practices will most improve safety? Evidence-based medicine meets patient safety. JAMA. 2002;288(4):501–507
38. Davis EM, Foral PA, Dull RB, Smith AN. Review of insulin therapy and pen use in hospitalized patients. Hosp Pharm 2013;48(5):396–405
39. American Society of Health-System Pharmacists and the Hospital and Health System Association of Pennsylvania. Professional practice recommendations for safe use of insulin in hospitals. 2004. Accessed Jan 2016. https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&cad=rja&uact=8&ved=0ahUKEwjflK2dgZHKAhUDPT4KHXXBDXgQFghCMAY&url=http%3A%2F%2Fpicsolution.ir%2Fwp-content%2Fuploads%2F2013%2F04%2FSafe-Use-of-Insulin-in-Hospitals.pdf&usg=AFQjCNE-cZolHpD6raqQDrAo41FqYe0imA&sig2=Hzy6i_LcN5fo4naGLOcTPg&bvm=bv.110151844,d.cWw
Chapter 5
Food, Fasting, Insulin, and Glycemic Control in the Hospital
Mary Korytkowski, MD,1 Boris Draznin, MD, PhD,2 and Andjela Drincic, MD3
1Division of Endocrinology and Metabolism, University of Pittsburgh, Pittsburgh, PA. 2Division of Endocrinology, Diabetes, and Metabolism, University of Colorado School of Medicine, Aurora, CO. 3Division of Diabetes, Endocrinology and Metabolism, Medical Director, The Nebraska Medical Center Diabetes Center, Omaha, NE.
DOI: 10.2337/9781580406086.05
Introduction
Diabetes treatment in the hospital poses unique challenges that differ from those encountered in the outpatient setting.1–5 These challenges arise from patient factors that include illness-related variability in insulin sensitivity, as well as system factors related to inconsistency in hospital procedures for insulin dosing and meal delivery, complicating the ability to achieve and maintain desired glycemic goals.3–7 Despite the demonstrated superiority of scheduled insulin therapy over sliding-scale insulin (SSI) regimens, the latter persists as a fallback strategy for many providers who may be unfamiliar or uncomfortable with basal-plus or basal-bolus insulin (BBI) regimens.8–13
A major challenge to insulin use in the hospital is related to variability in food intake and carbohydrate exposure, with associated concerns for hypoglycemia when patients are not eating regular meals.14–16 Appropriate timing of prandial insulin administration can be complicated by lack of coordination in the timing of food tray delivery with point-of-care (POC) measures of capillary blood glucose (BG) and insulin administration, tasks that are performed by personnel from different departments in the hospital setting. Some patients are unable to ingest prescribed calories because of lack of appetite or dislike of hospital meals. Other patients may skip meals and instead consume snacks and meals brought to the hospital by friends or family members without informing nursing personnel of the need for prandial insulin.14
One of the most frequently encountered scenarios in the care of individuals with diabetes treated with noninsulin or insulin therapy in the hospital is what to do during periods of fasting or inability to take oral nutrition.3,4,15 Scheduled periods of fasting for diagnostic testing or surgical procedures are frequent occurrences in the inpatient setting. Although there is a general awareness of the need for continuation of some form of glucose-lowering therapy during periods of fasting in patients with diabetes, there is uncertainty about how to modify therapy in a way that prevents both hyperglycemia and hypoglycemia.7,15,17 Many patients are admitted through same-day surgery units for short outpatient procedures as well as complicated prolonged procedures that require postoperative hospitalization. Therefore, recommendations for adjustments to a glycemic management regimen often begin at home.15
This chapter will review an approach to adjustments in noninsulin and insulin therapies during periods of fasting and will address the issue of timing of insulin therapy with meals. This section starts with a patient case followed by a discussion of how to modify BBI therapy during a 2-day period of consumption of only clear liquids before a planned surgical procedure. For purposes of this discussion, NPO (nil per os: nothing by mouth) will be used whenever a patient is placed in a fasted state.
Issues to Consider When Writing Consult Notes and Making Recommendations
Patient Case A 64-year-old woman with insulin-treated type 2 diabetes (T2D) is admitted to the hospital for aortic valve replacement. She will be receiving only clear liquids for 2 days before the procedure and will remain NPO after midnight before the procedure. Her admission weight is 76 kg (167 lbs). Her HbA1c 1 month before admission was 8.7%. Her home insulin regimen consists of detemir insulin 40 units at 8 p.m. with fixed doses of 14 units of insulin aspart prior to each meal. She reports home fasting glucose levels of 130–150 mg/dL with daytime values that range between 120 and 260 mg/dL. You are asked to make recommendations regarding her insulin regimen.
Insulin Modifications for Patients on Clear Liquid Diets
Clear liquid diets include the use of fruit juices, sodas (lemon-lime soda and ginger ale), gelatin, popsicles, and broth. Many of these foods are caloric beverages with high sugar content that require doses of nutritional insulin to maintain glycemic control (Table 5.1).
Similar to insulin glargine, detemir is a basal insulin, ideally covering insulin needs in the absence of any food intake.18,19 In the majority of instances, there is no need to reduce the dose of the basal insulin for a clear liquid diet. The patient in this case was on fixed doses of premeal insulin with wide variability in her glycemic control at home, likely representing variability in her caloric consumption at home.
To determine a premeal insulin dose for a clear liquid diet, calculate the prandial insulin dose according to planned carbohydrate intake (Table 5.1).16,20 For example, 4 ounces of apple juice or lemon-lime soda contains ~15 g of carbohydrate. The ratio of insulin-to-carbohydrate intake (insulin-to-carbohydrate ratio [ICR]) could be based on the total daily dose (TDD) of basal insulin using one of several published formulas. Of these, the following formulas are the easiest to use:21
400/TDD basal insulin (5.1)
2.8 × weight (lb)/TDD basal insulin (5.2)
Although these formulas have been accepted and used in many clinical trials, other authors have proposed dosing formulas that call for higher mealtime insulin delivery.20,22–26 Caution is advised in using any formula because of differences in patient populations (type 1 diabetes [T1D] vs. type 2 diabetes [T2D]) and insulin delivery devices (subcutaneous injections vs. insulin pumps) used in these prior studies, with some including lean patients with T1D using insulin pump therapy.26
For the patient in this case, consumption of 12 ounces of ginger ale (32 g), 1 cup of gelatin (19 g), and 1 popsicle (17 g) at a meal provides a total carbohydrate intake of 68 g (Table 5.1). Using the first formula (i.e.,