Department of Anesthesiology & Perioperative Care: School of Medicine: University of California, Irvine

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Guidelines for Diabetics

If you are a diabetic, it is better to have your procedure scheduled early in the day or for a first case, especially if your diabetes is difficult to manage.

Many of our patients have diabetes, and if there are other diabetics scheduled in the same room, you may not be the first. For early-morning short procedures where you may still be expected to eat according to your usual meal plan, it is easiest just to take your morning oral medication or insulin and food after the procedure (as if you just got up late that day).

Shortening the intervals between later meals may compensate for this delay and gradually realign your mealtimes back to the usual schedule. This is the easiest for both patients and physicians because it has the least disrupting effect diabetes management.

Multiple factors influence blood glucose management. Specific guidelines will not fit every patient's needs. Consider the following criteria when making decisions with your physician and anesthesiologist about managing your diabetes when you must have a procedure.

Type

Do you have type 1 or type 2 diabetes mellitus? Diabetics who are type 1 should never have all insulin withheld.

Age of Onset and Duration of Diabetes

Both types 1 and 2 can occur at any age. Long duration (over 10 years with type 2) usually means greater insulin deficiency and/or greater insulin resistance. Type 1 diabetics can become more resistant to insulin and type 2 diabetics can become insulin deficient.

Body Type

Overweight people (both types) have more insulin resistance and require larger amounts of insulin for control.

Diabetes Medication

What type/amount/frequency of medication(s) are you taking?

Insulin Therapy

If continuous insulin therapy started within 6 months of diagnosis this usually means severe insulin deficiency or type 1.

Other Related Conditions

Tell your anesthesiologist if you have any complications to help avoid worsening them during procedure. Diabetic feet need protection to prevent pressure ulcers; renal insufficiency means renal blood flow must be protected; renal failure means we need to coordinate with your dialysis schedule; any infection may mean we need to change insulin management.

Glucose Control

Blood glucose control, not just a recent blood glucose levels, is important - we like to assess a recent hemoglobin A1c result and possibly your glucose log, then check glucose in pre-operative area.

Awareness

Are you able to recognize symptoms of low blood glucose and how to treat yourself, or do you need assistance?

Guidelines for Preoperative and Pre-procedure Preparation of Adult Patients with Diabetes Mellitus

Type 1 Diabetes Mellitus

Basal Insulin

Always continue basal insulin source (NPH, Lente, Ultralente, glargine (Lantus), detemir (Levemir), insulin pump or intravenous insulin infusion) in order to prevent ketoacidosis. Serious problems result from a lack of insulin.

Non-Peaking Basal Insulin

Type 1 patients on glargine (Lantus) or detemir (Levemir) can be considered to be on a "poor man's pump" which should be continued without diminishing the dose. Glargine is usually taken every 24 hours at night as a basal dose, does not peak, and is dosed unrelated to food intake. Detemir is usually taken every 12 hours, does not peak, and is dosed unrelated to foot intake.

  • For type 1 patients taking glargine at bedtime, take the usual dose the night before procedure
  • For type 1 patients taking glargine in the morning, take the usual dose the morning of procedure, unless your doctor is having you take more than a basal rate dose
  • For type 1 patients taking detemir, take the usual dose the morning of procedure, unless your doctor is having you take more than a basal rate dose

Peaking Basal Insulins

Dose may need to be adjusted for peaking insulins (NPH, Lente, Ultralente).

  • Take usual dose of NPH insulin the night before procedure
  • If you will be an inpatient, you should have an IV so that we can give you glucose or dextrose when you need it. We may give you 2/3 the usual dose of NPH insulin the morning of the procedure.
  • If you will be an outpatient, don't take insulin until you come to the hospital and have an IV started: we will test your blood sugar and may give 2/3 usual dose of NPH insulin the morning of procedure. You may require some intravenous dextrose to decrease risk of hypoglycemia. After the procedure, we will test your blood glucose and give the remainder of usual morning dose of NPH insulin depending on whether or not you will be able to eat, with extra rapid- or short-acting insulin as needed.
  • If you take long-acting peaking insulin (such as extended insulin zinc [Ultralente]) and short-acting insulin, we may switch you to an intermediate-acting type (NPH) a day or two before planned surgery if we feel this is appropriate.

Short Acting Insulin

Do not take short acting (Regular, Humalog or Novalog) injected insulin the morning of procedure.

Continuous Insulin

If you are treated with continuous insulin infusion therapy (insulin pumps) you may be treated with your usual basal infusion rate.

Complex Patients

We may need to involve your endocrinologist or endocrinology consultant if you are considered (or consider yourself to be) a complex or high risk patient.

For a long procedure (over 4 hours)

We may omit all subcutaneous insulin and start an intravenous insulin infusion the morning of the procedure; we have an ICU insulin infusion protocol we can use. Intravenous regular insulin is indicated during the perioperative period for previously insulin-treated patients undergoing long, complex operative procedures; patients who require emergency surgery while in ketoacidosis; and patients with unstable type 1 diabetes.

Type 2 Diabetes Mellitus

Short-acting insulin

Omit fast- or rapid-acting injected insulin the morning of procedure.

NPH insulin

Follow guidelines for type 1 diabetes above.

Glargine insulin (Lantus) or detemir insulin (Levemir)

Type 2 diabetes patients may be prescribed glargine insulin as a basal dose OR may have a larger dose prescribed (sometimes in morning and evening divided doses) to compensate in part for meals. They may alternatively be on detemir insulin which lasts up to 24 hours but is usually prescribed in twice daily doses.

  • For patients taking glargine at bedtime, take approximately 1/2 to 3/4 your usual dose the night before procedure.
  • For patients taking glargine in the morning, take approximately 1/2 to 3/4 your usual dose the morning of procedure.
  • For patients taking detemir in the morning, take your usual dose the morning of procedure unless your doctor advises you to take a smaller dose.

For a long procedure (over 4 hours)

We may stop all subcutaneous insulin and start intravenous insulin infusion the morning of the procedure.

Oral medications

  • Do not take glucophage XR the evening before the procedure or for longer if you will not be able to eat for longer or will be unable to take your usual meal the day before as part of a prep for surgery.
  • Do not take glucophage or glucophage XR the morning of the procedure.
  • Changes in kidney function during major surgery may mean that Metformin (glucophage) should not be restarted for 72 hours postoperatively, when we are certain your kidney function has returned to normal.
  • Diabenase (chlorpropamide) should not be taken the night before or the morning of surgery.
  • Do not take Glipizide, Glyburide, Glimepride, Prandin, Starlix, Precose, Glyset or Voglibose the morning of your procedure; they can be restarted when you can eat your usual meals.
  • Avandia or Actos may sometimes be continued (for minor outpatient surgery) if this are your only diabetes medication, unless you have problems or may have problems with fluid retention.
  • If you take two or more oral diabetes drugs you may be placed on insulin temporarily while you are in the hospital.
  • If you have heart disease and take either glibenclamide (Glyburide) or glucophage (Metformin), tell your anesthesiologist, because there is evidence that these medications do not protect you as well as other diabetes medications from heart problems during and after surgery.
  • Other oral diabetes medications (Byetta, Symlin, Galvus, or Januvia) should not be taken on the morning of your procedure or restarted until you are eating your usual meals.
  • If you take a medication for high cholesterol or high lipids in your blood, you should continue to take the medication unless your doctor has a specific reason to ask you to stop it.