- Admission A1c Interpretation
- Inpatient Glucose Goals
- Medications to Use and Avoid
- Enteral and Parenteral Feedings
- Glucocorticoid Use
Why do glucose levels go up in the hospital?
- GH, cortisol, catecholamines and glucagon all increase under physiologic stress.
- This increases gluconeogenesis, glycogenolysis, and insulin resistance increases.
Do higher glucoses impair outcomes?
- Glucose > 180 impairs PMN function
- Impaired protein synthesis/healing
- Dehydration due to fluid shifts and glucose-related diuresis
- Impaired myocardial metabolism
- Increased inflammatory cytokines
References: Moghissi E, Diabetes Care 2009; 32:1119ff. and Umpierrez G, J Clin Endocrinol Metab 2012; 97:16
Hypoglycemia can also be an issue in the hospital:
- They’re NPO
- Medication errors (insulin dosing errors are common)
- Liver dysfunction (most important glucose-producing organ in the body)
- Renal dysfunction (second most important glucose-producing organ, and metabolizes insulin)
- Diet changes in the hospital
- Low glucose causes a catecholamine spike, and then myocardial O2 demand and arrhythmia risk.
ADMISSION A1C INTERPRETATION
- If A1c < 5.7% and inpatient glucose high = stress hyperglycemia but no DM.
- A1c 5.7-6.4% and inpatient glucose high = stress hyperglycemia AND pre-diabetes.
- A1c 6.5-8.0% and inpatient glucose high = stress hyperglycemia and well-controlled diabetes.
- A high A1c on admission means you need to address their outpatient regimen at discharge!
WHAT ARE INPATIENT GLUCOSE TARGETS?
- Goal is fasting < 140, random < 180.
- Insulin should be initiated if any blood glucose readings are > 180.
- Non-critically ill pts: fasting goal 90-140, all BGs < 180.
- Critically ill patients: 140-180.
MEDICATIONS TO USE AND TO AVOID IN DIABETIC INPATIENTS
- Metformin and glipizide should be stopped on admission; basal and CF insulin should be substituted.
- Type I diabetes: Insulin only
- Basal – bolus insulin regimen
- Basal insulin should be given whether they are NPO or not! Give 75-100% of home dose depending on:
- home control (A1c) – if well-controlled at home, drop the dose to 75%; if poor control, may need 100%.
- eating or NPO status
- if no records or not sure where to start: 0.1-0.2 U/kg weight; approx 50% of total daily dose of insulin.
- Best time to give meal-time CF insulin is about 15 mins prior to a meal, but this is not always practical even in the hospital. It’s okay to give the CF right after the meal for safety – at least you know they ate something.
- Home mealtime (prandial) dose continued, or…C:I ratio (carbohydrate:insulin) of 15 g CHO: 1 unit insulin.
- Correction component – with the CF or alone.
- use home correction factor or CF of 50:1 – 1 unit per 50 mg/dL over 150 mg/dL.
- Type II diabetes: more variation – lifestyle only, PO meds, insulin regimens…
- Insulin is the preferred agent for achieving glucose control in hospitalized patients.
- Non-insulin therapies should be discontinued in most patients.
- SUs: stop almost always (risk of no meal)
- meglitinides: stop almost always (risk of no meal)
- metformin: usually stop (chance of AKI)
- TZDs: usually stop (risk of HF or edema)
- new agents – usually stop as well
- Situation 1: Lifestyle management only, A1c well-controlled
- POC glucose measurement QID x 24-48h, continue if hyperglycemia
- If BG > 180 – correction doses with short-acting insulin (50:1 correction factor, 1 unit per 50 mg/dL above target)
- Start basal insulin if 3+ correction doses are needed per day. Start at 0.2-0.3 U/kg/d.
- If postprandial sugars high despite the above, start prandial/nutritional insulin too with a C:I ratio of 15:1.
- Situation 2: Uncontrolled on lifestyle mgmt or on non-insulin treatment (PO agents)
- QID testing
- Start basal right away 0.2-0.3 U/kg/day
- Correction insulin if glucoses > 180 at ratio of 25:1 above target 150 mg/dL
- Add mealtime insulin if post-prandial sugars are still high.
- Situation 3: Basal insulin +/- PO agents
- Start basal insulin (home dose usually okay or 0.2-0.3 U/kg/d)
- Correction dose if sugars > 180 (25:1 ratio)
- Mealtime insulin if post-prandial sugars high (C:I ratio of 15:1)
- Situation 4: Basal / Bolus insulin therapy
- Basal insulin at all times – if you stop it, they’ll get ketotic
- Treat this a lot like T1DM
- Use 75-100% of their home dose depending on their A1c (lower doses if well-controlled)
- Mealtime insulin and correction factors: home doses or C:I 10:1 (mealtime)
HYPERGLYCEMIA IN ENTERAL AND PARENTERAL NUTRITION
- BG testing every 4-6 hours for 24-48h in ALL patients on EN/PN.
- Start scheduled insulin if BG > 140 and needing persistent correction doses.
- Use an insulin that has a duration of action consistent with the duration of feeding!
- Aspart, lispro – bolus feedings
- Glargine or 70/30 BID-TID – continuous feedings
- C:I ratio is 15:1 – CHO 15 gram for each unit of insulin if pt diabetic (25:1 if non-DM hyperglycemia). CHO content should be available from the chart or dietician.
- Correction doses q 6 hours: CF 50:1 (1 unit for every 50 mg/dL above target 150 mg/dL).
- 70/30 or NPH BID to TID is appropriate for continuous tube feeding. This is preferred to glargine or detemir because tube feeds are sometimes stopped!
- Dose is C:I ratio of 15:1 (DM) or 25:1 (non-DM).
- Correction dose q 6 hours CF 50:1 to target of 150 mg/dL
- Pt getting TF with 282 g CHO/day
- At ratio of 15:1, he needs 18 units of insulin daily
- So, give NPH 6 units TID.
- Short-acting insulin can be given in TPN! Use C:I ratio of 15:1.
- If EN/PN is stopped (inadvertently or purposefully), be aware of when you gave your last insulin and what kind of insulin – will need to cover that insulin with D5 or D10 (try to give same CHO content as EN/PN).
GLUCOCORTICOIDS AND HYPERGLYCEMIA
- Typical pattern with QD prednisone or methylprednisolone: fasting glucose is okay, but post-lunch and post-dinner levels very high. Usually starts to decrease again after 14 hours or so.
- A nice way to correct this is: morning NPH and as-needed pre-meal correction insulin.
- BG testing QID x 24-48 hours after starting glucocorticoid therapy REGARDLESS of their hx of diabetes!
- Start by giving CF 25:1 to target 150 mg/dL
- If needing persistent CF, then start basal insulin (consider NPH with the morning dose).
- NPH dose 10 U (sensitive) or 20 U (resistant) per 40mg of prednisone/methylprednisolone
- Give NPH BID if they’re getting BID steroids.
- This can be added even if the patient is on an insulin pump or as an add-on to an existing insulin regimen!
- Intra-articular steroids will also raise sugar (obviously), but the rise is all day long, not the kinetics seen with PO prednisone.
- Reference: Seggelke S, J Hosp Med 2011; 6:175-6
– From Rocky Mountain Hospital Medicine, 2016, McDermott