Diabetes mellitus
Anesthetic relevance


Anesthetic management

Preoperative HgA1c value Preoperative glucose value Preoperative medication adjustment Insulin administration Post-operative glucose



Signs and symptoms

Excessive thirst Polyuria Polydypsia Glucosuria Peripheral neuropathy Ocular degeneration Cardiovascular disease


HgA1c Fasting glucose


Oral anti-hyperglycemics Exogenous insulin administration

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Diabetes is an endocrine, metabolic disorder marked by high levels of blood glucose. Three classifications of diabetics exist:

  1. Type 1 Diabetes, where an immune mediated destruction of pancreatic beta cells occurs causing a total reduction in endogenous insulin and thus causing hyperglycemia
  2. Type II Diabetes, where patients experience increasing insulin resistance for the level of endogenous insulin thus causing hyperglycemia
  3. Gestational Diabetes in which hyperglycemia occurs in the second or third trimester of pregnancy.

The diagnosis of diabetes is made based on fasting blood glucose levels and hemoglobin A1c levels. The diabetic population in the United States is both increasing in incidence and prevalence within the last decade. This disease affects multiple organ systems that have anesthetic implications including cardiovascular health, renal disease, peripheral neurologic function, and gastrointestinal emptying requiring preoperative optimization and intraoperative control.

Cystic fibrosis patients have an acquired form of diabetes as the most common co-morbidity of cystic fibrosis (20% of adolescents and 40-50% of adults).[1]

Anesthetic implications

Preoperative optimization

  • No overt indications for case cancellations for poorly controlled diabetes[2][3] except if patients are in diabetes ketoacidosis (DKA) or hyperosmolar osmotic non-ketotic crisis (HONK)
  • Postoperative blood glucose greater than 140 mg/dL is found in as many as 40% of patient undergoing non-cardiac surgery and almost 25% of those patients demonstrate a blood glucose greater than 180 mg/dL during the operative and immediate post-operative period[4][5]
  • Data shows mixed reduction of mortality with good blood glucose control in surgical patients[6], but a reduction in surgical site infection risk[7]
  • Consider case delay alongside surgery team if BG > 250 mg/dL and case is elective and a prothesis or synthetic biofilm will be inserted into the patient during surgery (i.e. prothesis, intraocular lens, joint replacement, graft, etc).
  • Obtain pre-operative HgA1c if one has not been obtained via primary care in last 3 months prior to surgery
    • If HgA1c > 8.0 - evidence shows greater incidence of post-operative hyperglycemia during patient recovery
Pre-operative medication adjustments:
Drug Class Medication Day before Surgery Day of surgery Notes
DPP-4 inhibitors Sitagliptin/Saxagliptin


Take Take


Acarbose/Miglitol Take Do not take
Sulfonylureas Glipizide/glyburide Take Do not take
SGLT-2 inhbitors dapagliflozin/canagliflozin


Hold 3 days prior

to surgery[8]

Do not take Can cause euglycemic DKA[9] if not stopped in advance of surgery
SGLT-2 inhibitors ertugliflozin Hold 4 days prior

to surgery[8]

Do not take Can cause euglycemic DKA[9] if not stopped in advance of surgery
Biguanides metformin/Metformin ER Take +/- take Hold if patient has renal/hepatic insufficiency, COPD or CHF or if

team anticipates potential for AKI or hepatic shock during case

GLP-1 agonist exenatide/exenatide ER Take Do not take
GLP-1 agonist dulaglutide Take Do not take
GLP-1 agonist semaglutide Take Do not take
GLP-1 agonist liraglutide Take Do not take
Amylin mimetics pramlintide Take Do not take
Long acting insulin Glargine/detemir/degludec Take 80% of dose Take 80% of dose Coordinate with patient's endocrinologist
U-500 insulin Take usual dose Take 50% of dose Coordinate with patient's endocrinologist
70/30 insulin Take usual dose Change to NPH

and give 50% of dose

Coordinate with patient's endocrinologist
70/25 insulin Take usual dose Change to NPH

and give 50% of dose

Coordinate with patient's endocrinologist
50/50 insulin Take usual dose Change to NPH

and give 50% of dose

Coordinate with patient's endocrinologist
NPH insulin Take usual dose Take 50% of dose Coordinate with patient's endocrinologist
Prandial insulin Take usual mealtime dose Do not take Coordinate with patient's endocrinologist
Insulin pump Set at 80% basal rate Coordinate with patient's endocrinologist

Intraoperative management

Institutional practices may vary, however the general principle is to perform close monitoring and maintain euglycemia. Stanford intraoperative glycemic care guidelines recommend targeting a blood glucose of 140-180 during surgery[10]. An interval of q2h is appropriate if the patient's blood glucose remains within this range. Sugars between 70-140 warrant closer q1h monitoring, and any sugar below 70 in most adult patients necessitates treatment with a dextrose bolus (e.g. 12.5 g of D50) with subsequent q15 min glucose checks.

For patients with hyperglycemia >180, the duration of surgery and level of critical illness can guide whether intermittent subcutaneous insulin vs continuous insulin infusion is appropriate for intraoperative management. Subcutaneous insulin (e.g. Humalog a.k.a. Lispro) is delivered every 2-3 hours based on a sliding scale (cannot be delivered more frequently due to the time to peak effect of insulin and risk of dose stacking). Continuous insulin infusions are generally titrated every hour with at minimum a rate of 0.5 units/hour running unless glucose levels fall below 100 mg/dL. Subcutaneous insulin management is not appropriate for patients with poor perfusion or those who have no change in glucose after 2 attempted doses.

Postoperative management

Continue sliding scale/insulin pump management post-operatively.

Related surgical considerations

Certain factors can predispose patients to being either insulin-sensitive or insulin-resistant intra-operatively. Factors that are associated with insulin-sensitivity include: new diagnosis; age >70 years old; BMI <25 kg/m2, eGFR <45 mL/min. Factors that are associated with insulin-resistance include: BMI >35 kg/m2; home TDD >80 units; steroids >20 mg prednisone/day[10].


Correctional dosing of insulin is based off of a patients total daily dose (TDD). This may already be known based off of a patients home regimen. For patients whose TDD is unknown, an adult's TDD can be approximated as 0.4U/kg/day[10].

From a patient's TDD, an insulin sensitivity factor (ISF) can be calculated that provides a patient's corrective dosing (i.e. the expected drop in glucose if a patient is given 1U of rapid-acting insulin).

ISF = 1800/TDD

As an example, a patient with a TDD of 48U will have an ISF of 37.5 (which can be rounded to 40). Therefore, one possible corrective dosing regimen could be 1U for every 40 >180 (assuming target glucose of 180).

Signs and symptoms

Intra-operatively, hypoglycemia can lead to cardiac arrhythmia and hemodynamic instability. Hyperglycemia has been shown to increase adverse post-surgical outcomes including surgical site infections, delayed wound healing, and increased length of stay[11].


Diagnosis of diabetes can be made by a variety of ways:

  1. Fasting plasma glucose ≥ 126mg/dL
  2. Two-hour plasma glucose ≥ 200mg/dL
  3. A1C ≥ 6.5 prior to initiating anti-hyperglycemic medications



Humalog (Lispro) is a rapid-acting agent commonly used in sliding scale regimens. It's onset occurs in <15 minutes. Its peak occurs in 30-90 minutes. Duration is generally between 3-5 hours (which is why dosing is performed no more frequently than every 2-3 hours).

Long acting agents include glargine (Basaglar/Lantus) and are typically dosed once a day in the evening as part of a home insulin regimen.


The diabetic population in the United States is both increasing in incidence and prevalence within the last decade. According to the 2017 National Diabetes Statistics Report from the Center for Disease Control (CDC), 10.5% of the U.S. population has diabetes with an estimated 21.4% of those who have the disease are still not diagnosed.[12]


  1. Association, American Diabetes (2021-01-01). "2. Classification and Diagnosis of Diabetes: Standards of Medical Care in Diabetes—2021". Diabetes Care. 44 (Supplement 1): S15–S33. doi:10.2337/dc21-S002. ISSN 0149-5992. PMID 33298413.
  2. Vann, Mary Ann (2014-06). "Management of Diabetes Medications for Patients Undergoing Ambulatory Surgery". Anesthesiology Clinics. 32 (2): 329–339. doi:10.1016/j.anclin.2014.02.008. Check date values in: |date= (help)
  3. Joshi, Girish P.; Chung, Frances; Vann, Mary Ann; Ahmad, Shireen; Gan, Tong J.; Goulson, Daniel T.; Merrill, Douglas G.; Twersky, Rebecca (2010-12). "Society for Ambulatory Anesthesia Consensus Statement on Perioperative Blood Glucose Management in Diabetic Patients Undergoing Ambulatory Surgery:". Anesthesia & Analgesia. 111 (6): 1378–1387. doi:10.1213/ANE.0b013e3181f9c288. ISSN 0003-2999. Check date values in: |date= (help)
  4. Frisch, A.; Chandra, P.; Smiley, D.; Peng, L.; Rizzo, M.; Gatcliffe, C.; Hudson, M.; Mendoza, J.; Johnson, R.; Lin, E.; Umpierrez, G. E. (2010-08-01). "Prevalence and Clinical Outcome of Hyperglycemia in the Perioperative Period in Noncardiac Surgery". Diabetes Care. 33 (8): 1783–1788. doi:10.2337/dc10-0304. ISSN 0149-5992. PMC 2909062. PMID 20435798.CS1 maint: PMC format (link)
  5. Levetan, C. S.; Passaro, M.; Jablonski, K.; Kass, M.; Ratner, R. E. (1998-02-01). "Unrecognized Diabetes Among Hospitalized Patients". Diabetes Care. 21 (2): 246–249. doi:10.2337/diacare.21.2.246. ISSN 0149-5992.
  6. Buchleitner, Ana Maria; Martínez-Alonso, Montserrat; Hernández, Marta; Solà, Ivan; Mauricio, Didac (2012-09-12). Cochrane Metabolic and Endocrine Disorders Group (ed.). "Perioperative glycaemic control for diabetic patients undergoing surgery". Cochrane Database of Systematic Reviews. doi:10.1002/14651858.CD007315.pub2.
  7. Kroin, Jeffrey S.; Buvanendran, Asokumar; Li, Jinyuan; Moric, Mario; Im, Hee-Jeong; Tuman, Kenneth J.; Shafikhani, Sasha H. (2015-06). "Short-Term Glycemic Control Is Effective in Reducing Surgical Site Infection in Diabetic Rats:". Anesthesia & Analgesia. 120 (6): 1289–1296. doi:10.1213/ANE.0000000000000650. ISSN 0003-2999. Check date values in: |date= (help)
  8. 8.0 8.1 Research, Center for Drug Evaluation and (2021-01-11). "FDA revises labels of SGLT2 inhibitors for diabetes to include warnings about too much acid in the blood and serious urinary tract infections". FDA.
  9. 9.0 9.1 Seger, Christian D.; Xing, Hanning; Wang, Libing; Shin, John S. (2021-01-14). "Intraoperative Diagnosis of Sodium-Glucose Cotransporter 2 Inhibitor–Associated Euglycemic Diabetic Ketoacidosis: A Case Report". A&A Practice. 15 (1): e01380. doi:10.1213/XAA.0000000000001380. ISSN 2575-3126.
  10. 10.0 10.1 10.2 "Intraoperative Glycemic Care Guidelines" (PDF).
  11. pubs.asahq.org https://pubs.asahq.org/anesthesiology/article/126/3/547/19751/Perioperative-Hyperglycemia-ManagementAn-Update. Retrieved 2022-08-03. Missing or empty |title= (help)
  12. "National Diabetes Statistics Report, 2020 | CDC". www.cdc.gov. 2020-09-28. Retrieved 2021-07-12.