Management of Glycemia During Hospitalization and Surgery
Do you have three minutes to improve your patients’ care? In this week’s Clinical Text excerpt, we begin a new series with The Diabetes Ready Reference for Nurse Practitioners. Please take a few minutes to check out our first selection which provides you with the critical information you need to manage patients’ blood sugars during hospitalization and surgery.
Do you know the protocols for managing glycemia during hospitalization and surgery?….
A. Diabetes increases the risk for comorbidities that often result in hospitalization, including coronary artery, cerebrovascular, and peripheral arterial disease; nephropathy; infection; and lower-extremity amputations, but management of diabetes too often becomes secondary to the condition that prompted the admission.
- Aggressive glycemic management with insulin may reduce morbidity in patients with severe acute illness, perioperatively, and following myocardial infarction. Insulin infusion is safe and effective for achieving metabolic control during major surgery, hemodynamic instability, and NPO status.
- Blood glucose goals during hospitalization:
- Critical care: Recommended 140–180 mg/dl, Acceptable: 110–140 mg/dl in select patients.
- Non-critical Care: Random less than 180 mg/dl, premeal <140 mg/dl
- Use of scheduled basal and meal insulin improves glycemic control compared with orders based on sliding-scale insulin coverage alone.
- Type 1 patients must receive basal insulin at all times despite reductions or absence of calorie intake and perioperatively to prevent diabetic ketoacidosis.
- Oral diabetes medications should be discontinued during hospitalization and may be resumed if patient is stable close to or after discharge. An A1C should be done to determine glycemic control prior to admission to assess home therapy.
B. Acute hyperglycemia in the hospital or outpatient/clinic setting
- May contribute to microvascular and macrovascular complications, prolong length of stays, and contribute to increased morbidity and mortality rates.
- Hyperglycemia and relative insulin deficiency caused by metabolic stress triggers tissue and organ injury via the combined effects of infection, direct fuel-mediated injury, and oxidative stress. Moderate to severe hyperglycemia (mean glucose >200 mg/dl [>11.1 mmol/l]) has been shown to cause or be related to:
- Immunosuppression (leukocyte dysfunction and reduced T-cell populations)
- Cellular injury/apoptosis
- Tissue damage
- Altered tissue/wound repair
- Patients with no prior history of diabetes found to have hyperglycemia (random blood glucose >125 mg/dl [>6.9 mmol/l]) should have an A1C. A1C >6.5% is diagnostic, A1C 5.7–6.4% should indicates high risk and requires outpatient followup.
A. Management of diabetes patients requiring surgery focuses on risk reduction by normalizing blood glucose levels during and after surgery. Perioperative hyperglycemia delays healing and increases risk of ischemia.
- Perioperative plasma glucose levels 80–110 mg/dl (4.5–6.1 mmol/l) reduce morbidity and mortality among critically ill patients in the surgical ICU. Adjust IV insulin and glucose for the individual’s insulin requirement titrated from frequent blood glucose values.
- Customary basal insulin dose is the minimum required to counteract insulin resistance and glucogenesis caused by stress. Additional insulin also will be needed to prevent excessive hepatic glucose release and decreased peripheral utilization while maintaining normal glucose levels and fluid and electrolyte balance.
- Glycemic control and therapy adjusted as appropriate for current therapy and type of surgery
- Additional assessments if needed, e.g., chest X ray, ECG, renal function, A1C
- Anesthesia consultation
- Type 2 treated with lifestyle changes alone
- Assess for metabolic control (A1C)
- Stabilize metabolic control with consistent carbohydrate meal planning and, if necessary, institute insulin therapy, similar to insulin-treated diabetes
- Schedule for surgery in morning
- Type 2 treated with oral agents
- Assess for metabolic control (A1C)
- If on long-acting sulfonylurea, change to shorter-acting sulfonylurea 1 week before surgery; may require insulin for stabilization. Discontinue oral agents during hospitalization and order insulin therapy
- Frequent blood glucose monitoring
- If control poor, stop oral agents and start insulin therapy
- Type 1 or type 2 treated with insulin
- May require admission 1 day before major surgery for assessment and possible stabilization of glycemic control
- Type 2 treated with lifestyle changes alone
- Patients undergoing elective surgery with local anesthesia (e.g., dental work) should eat only after surgery.
- Patients treated with lifestyle changes only or oral agents who are in good metabolic control usually don’t require insulin.
- Withhold food and short-acting insulin and continue basal insulin as insulin glargine or via insulin pump. If patient is managed in some other manner, they should be switched to a basal- bolus program before an elective procedure.
- Monitor blood glucose 1–2 times/hour initially, reducing frequency as appropriate.
- Place on IV insulin and glucose several hours preoperatively and maintain at <180 mg/dl (5.5–8.3 mmol/l).
D. Emergency surgery requiring general anesthesia: there is usually sufficient time to optimally evaluate and stabilize the patient. DKA can be treated concurrently with surgery.
E. Intravenous infusion of insulin rather than subcutaneous insulin administration is indicated to allow careful control of the amount and speed of insulin delivery and circumvent problems with subcutaneous absorption in the event of shock. One approach is provided on following pages. Follow your hospital’s protocol for intravenous insulin.
- Four to 8 hours before surgery, keep patient NPO, omit usual SC insulin, and insert IV line. Start infusion of 6.25 g/hour glucose (125 ml/hour D5 0.45% normal saline [NS] with 20 mEq KCl/l). Administer insulin as follows:
- Deliver 50 units regular insulin in 500 ml NS controlled with an IV regulator pump.
- Piggyback insulin line into the D5 0.45% NS line.
- Deliver at a rate (unit/hour) equal to (blood glucose [BG] mg/dl – 60) × 0.02 (or [BG mmol/l – 3.3] × 0.02), where 0.02 is the sensitivity factor (SF).
- Monitor BG hourly and adjust rate per formula.
- If BG is not decreasing or increases to >150 mg/dl (>8.3 mmol/l), increase SF by 0.01.
- If BG is <100 mg/dl (<5.5 mmol/l), decrease SF by 0.01.
- If BG is <80 mg/dl (<4.4 mmol/l), give IV D50W equal to (100–BG mg/dl) × 0.3 ml or (5.5–BG mmol/l) × 0.3 ml.
- Continue IV insulin as per formula with new SF.
- Repeat BG in 30 minutes.
- After surgery
- Continue IV insulin and glucose (D5 0.45% NS) infusion until 2 hours after oral feeding is resumed. If patient is NPO for several days, infuse sufficient glucose (150 g/day in adults; 2–4 g/kg/day in children) to meet minimal catabolic needs. Adjust the insulin infusion as per above to maintain BG 100–150 mg/dl (5.5–8.3 mmol/l).
- Transition to basal insulin such as glargine plus preprandial rapid-acting insulin when patient is able to eat.
- Long-acting insulin should be given in a dose equal to the average rate per hour of IV insulin infusion over the past 2–6 h × 12, e.g., (120–60) × 0.03 × 12 = 22 units if the last multiplier was 0.03 and the average BG was 120 mg/dl.
- Rapid-acting insulin should be given after the patient has eaten and in proportion to amount eaten at 1 unit per 10 g carbohydrate.
- Monitor BG at each meal, bedtime, and 3:00 a.m. Correction doses of rapid-acting insulin should be given for any BG >150 mg/dl (>8.3 mmol/l), per the formula Correction dose (units) = (BG mg/dl – 100)/correction. Correction factor = 1700/daily insulin.
- For insulin pump patients: resume basal rate and give boluses as per carbohydrate intake plus correction formula as above or according to the patient’s existing correction factor.
Copyright © 2012 American Diabetes Association. From Diabetes Ready Reference for Nurse Practitioners. Reprinted with permission from The American Diabetes Association. To order this book call 1-800-232-6733 or order online at http://www.shopdiabetes.org