Treatment algorithm

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups: see disclaimer

ACUTE

critically ill or unplanned surgery or in ICU: hyperglycemia

1st line – insulin + treatment of comorbid illness

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ACUTE
|
critically ill or unplanned surgery or in ICU: hyperglycemia
1st line – 

insulin + treatment of comorbid illness

Effective management of hyperglycemia is associated with a decreased length of intensive care unit (ICU) and hospital stay.[3][11]​​​ However, multiple trials have shown conflicting evidence about what the goals of glycemic control should be for critically ill individuals; outcomes from this research has varied from advising tight glucose control in the intensive care unit, to suggesting there is no mortality benefit of intensive insulin therapy and that a higher mortality may even be associated with tight glycemic control.[21][22][23]​​

The American Diabetes Association (ADA) recommends the glycemic goals for most critically ill individuals with hyperglycemia to be 140-180 mg/dL [(7.8-10.0 mmol/L]), with more stringent goals (110-140 mg/dL [6.1-7.8 mmol/L]) for selected critically ill individuals as long as this can be attained without significant hypoglycemia.[1]

The Canadian Diabetes Association recommends target glucose levels between 106 and 180 mg/dL (6.0 and 10.0 mmol/L) for most critically ill hospitalized patients.[2]

​​Intravenous insulin is recommended for all critically ill patients with hyperglycemia.[20] In patients with type 1 diabetes, withholding insulin may lead to ketoacidosis. Infusion of dextrose for nutrition, along with intravenous insulin administration, is essential.

Several intravenous insulin infusion protocols have been devised, the end results are similar in all studies, and each institution should choose the one that fits its needs and resources.[1]​​[21][34][35] Yale Insulin Infusion Protocol Opens in new window

Hypoglycemia should be avoided.

A pediatric endocrinologist should be consulted for children.

Consult local protocols for guidance on suitable insulin doses and regimens.

Primary options

insulin regular: intravenously

Plus – supportive care

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ACUTE
|
critically ill or unplanned surgery or in ICU: hyperglycemia
Plus – 

supportive care

Treatment recommended for ALL patients in selected patient group

Supportive care should address electrolyte imbalances, nutritional needs, and fluid balance.

Electrolytes should be monitored and corrected as required. Potassium should be added to intravenous fluids according to local floor protocols to prevent and treat hypokalemia.

In all patients, adequate nutrition and fluid replacement should be ensured. Total parenteral nutrition (TPN) may be required in patients who are unable to take orally. In these cases insulin can be added to the TPN or administered as a separate intravenous infusion. Patients receiving continuous enteral support may obtain better glucose control with a basal insulin plus regular insulin in place of a short-acting insulin due to a regular insulin's longer duration of action. In patients with type 1 diabetes, a dextrose-containing intravenous fluid is appropriate, along with insulin administration.

Plus – follow-up and optimization of outpatient antidiabetic treatment

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ACUTE
|
critically ill or unplanned surgery or in ICU: hyperglycemia
Plus – 

follow-up and optimization of outpatient antidiabetic treatment

Treatment recommended for ALL patients in selected patient group

Measurement of HbA1c is valuable in determining the plan at discharge. A high HbA1c indicates poor preexisting control and suggests need for increased or modified antidiabetic therapy (e.g., starting insulin or maximizing oral drugs).[3][8]​​

A wide range of therapy is available for long-term diabetes management. Some patients may need to continue taking insulin at home until complete recovery allows a transition to other therapies.[20]

Patients without known diabetes also need follow-up blood sugar levels and possible continued treatment.

stable noncritical illness: uncontrolled hyperglycemia

1st line – insulin + treatment of comorbid illness

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ACUTE
|
stable noncritical illness: uncontrolled hyperglycemia
1st line – 

insulin + treatment of comorbid illness

Insulin is recommended for hyperglycemia in hospitalized patients.[1]​ Blood glucose targets are: <140 mg/dL (<7.8 mmol/L) premeals, and random blood glucose <180 mg/dL (<10.0 mmol/L).[1]​​[3] The insulin regimen should be reassessed when glucose levels are <100 mg/dL (<5.6 mmol/L), and modified when glucose levels are <70 mg/dL (<3.9 mmol/L). Use of insulin on the general floor should be based on a basal-bolus approach.[1]​​[24]

Subcutaneous insulin (rapid- or short-acting) given before meals is preferred if the patient has adequate oral intake.

The ADA recommends that either basal insulin or basal plus bolus correctional insulin may be used in noncritically ill hospitalized patients with poor oral intake or those who are taking nothing by mouth.[1]

Second-generation basal insulins, such as insulin glargine (300 units/mL) and insulin degludec (100 units/mL and 200 units/mL), have lower peak-to-trough ratios, have longer duration of action than the first-generation basal insulins, and provide less glycemic variability. Patients who use these preparations can be continued on these while in the hospital.[26][27]

Several randomized trials have shown that a basal-bolus insulin regimen is more effective in controlling hyperglycemia than sliding scale insulin alone in noncritically ill patients admitted to the hospital.[46][47]​​ The Endocrine Society recommends that adults with diabetes treated with diet or noninsulin medications who experience hyperglycemia >140 mg/dL (>7.8 mmol/L) may begin initial therapy with correctional insulin or scheduled insulin to maintain glucose targets in the range of 100-180 mg/dL (5.6 to 10.0 mmol/L). This target of 100-180 mg/dL (5.6 to 10.0 mmol/L) is also the same for adults with insulin-treated diabetes prior to admission who are hospitalized for noncritical illness.[4]​ The ADA recommends that, for noncritically ill individuals, insulin therapy should be started or intensified to treat persist hyperglycemia if blood glucose readings are ≥180 mg/dL (≥10.0 mmol/L) on two separate occasions within 24 hours.[1]​ Note that sliding scale insulin alone is strongly discouraged in the inpatient setting.[1]​​

For patients who were on insulin at home, their home doses can be added up to give their total daily insulin dose.

Long-acting insulin is given once or twice daily. Rapid-acting insulin should be given in divided doses before each meal. Rapid-acting insulin should not be given if the patient is not able to eat.[24]

For regimens using intermediate-acting insulin, two-thirds of the total daily dose is given in the morning (further divided into two-thirds NPH insulin and one third fast-acting insulin), and one third in the evening (further divided into half fast-acting with the evening meal and half NPH at bedtime).[24]

One study suggests that basal insulin plus sliding scale is an option for type 2 diabetes. In 375 patients with type 2 diabetes randomized to receive either basal (glargine) plus sliding scale insulin (glulisine), basal (glargine) and scheduled mealtime plus correction sliding scale insulin (glulisine), or sliding scale insulin alone (regular insulin), basal plus sliding scale and basal plus scheduled mealtime plus sliding scale achieved the same glycemic control, and performed better than sliding scale alone.[28]

The use of sliding scales alone is not recommended, although they might be used on occasion for 24 hours to determine the insulin requirements in some patients. Additionally, sliding scales alone can be considered for patients hospitalized with noncritical illness and no history of diabetes with only mild hyperglycemia >140 mg/dL but <180 mg/dL.[4]​​

Hypoglycemia should be avoided by regular monitoring of blood glucose and changes in therapy as needed (e.g., reducing insulin).

A pediatric endocrinologist should be consulted for children.

Consult local protocols for guidance on suitable insulin doses and regimens.

Primary options

insulin aspart: subcutaneously before each meal

or

insulin glulisine: subcutaneously before each meal

or

insulin lispro: subcutaneously before each meal

-- AND --

insulin NPH: subcutaneously twice daily, preferably in the morning and at bedtime

or

insulin glargine: subcutaneously once daily, preferably at bedtime

or

insulin detemir: subcutaneously once daily, preferably at bedtime, or twice daily

or

insulin degludec: subcutaneously once daily

Plus – supportive care

Back
ACUTE
|
stable noncritical illness: uncontrolled hyperglycemia
Plus – 

supportive care

Treatment recommended for ALL patients in selected patient group

In all patients, adequate nutrition and fluid replacement should be ensured. Total parenteral nutrition may be required in patients who are not able to take orally. In patients with type 1 diabetes, a dextrose-containing intravenous fluid is appropriate, along with insulin (intravenous preferred).

Potassium should be added to intravenous fluids according to local floor protocols to prevent and treat hypokalemia.

Hypoglycemia should be avoided by regular monitoring of blood glucose.

Plus – follow-up and optimization of outpatient antidiabetic treatment

Back
ACUTE
|
stable noncritical illness: uncontrolled hyperglycemia
Plus – 

follow-up and optimization of outpatient antidiabetic treatment

Treatment recommended for ALL patients in selected patient group

Measurement of HbA1c is valuable in determining the plan at discharge. A high HbA1c indicates poor pre-existing control and suggests need for increased or modified antidiabetic therapy (e.g., starting insulin or maximizing oral drugs).[3][8]​​

A wide range of therapy is available for long-term diabetes management. Some patients may need to continue taking insulin at home until complete recovery allows a transition to other therapies.[20]

Patients without known diabetes also need follow-up blood sugar levels and possibly continued treatment.

stable noncritical illness: well-controlled known diabetes

1st line – continuation of usual antidiabetic regimen + treatment of comorbid illness

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ACUTE
|
stable noncritical illness: well-controlled known diabetes
|
eating normally
1st line – 

continuation of usual antidiabetic regimen + treatment of comorbid illness

Insulin is the preferred form of treatment for most inpatients; however, oral drugs may be used in selected patients.[20]

Patients on metformin should be closely monitored given its contraindications (renal impairment, heart failure, contrast studies), though will probably need to be discontinued. Sodium-glucose cotransporter-2 (SGLT2) inhibitors have been associated with diabetic ketoacidosis, including euglycemic diabetic ketoacidosis, and it is recommended to stop them upon admission, and 3 days prior to scheduled surgery.[38] However, the use of SGLT2 inhibitors in the hospital setting remains a subject of investigation.[39] The ADA recommends that patients with type 2 diabetes hospitalized with heart failure be started or continued on an SGLT2 inhibitor after recovery from acute illness if no contraindications are present.[1] Dipeptidyl dipeptidase-4 inhibitors with or without long-acting basal insulin may be continued in non-critically ill hospitalized patients with mild to moderate hyperglycemia.[40][41][42]​​ Thiazolidinediones are not recommended in patients with fluid retention as part of their presenting condition. Drugs with hypoglycemic effects may be difficult to dose appropriately with changes in the patient's feeding status. General blood glucose targets are: <140 mg/dL (<7.8 mmol/L) premeals, and random blood glucose <180 mg/dL (<10 mmol/L), if these can be safely achieved without hypoglycemia.[1]​​[3]

Type 1 diabetes: inpatients who have well-controlled blood glucose levels can continue taking their usual insulin regimen. The ADA recommends that an insulin schedule with basal and correction components is necessary for all hospitalized people with type 1 diabetes, even when taking nothing by mouth, with the addition of prandial insulin when eating.[1]​ A reduction of the mealtime insulin doses can be made depending on food consumption.

Type 2 diabetes: most inpatients are switched to basal-bolus insulin regimen, but well-controlled patients who are eating may be able to continue on oral antidiabetic drugs, if there are no contraindications and if it can be assured that the patient's feeding status will not be switched to nil by mouth. For patients taking metformin, switching to insulin would be considered a safer option.

Patients admitted for elective surgery on oral antidiabetic drugs usually stop their oral drugs and start on intravenous insulin intraoperatively or post-operatively, then transition to subcutaneous basal-bolus insulin once they start eating.

Use of insulin on the general floor should be based on a basal-bolus approach.[1]​​[24]

For subcutaneous insulin, basal insulin can either be long-acting (glargine, detemir, degludec) or intermediate-acting (NPH). Second-generation basal insulins, such as insulin glargine (300 units/mL) and insulin degludec (100 units/mL and 200 units/mL), have lower peak-to-trough ratios, have longer duration of action than the first-generation basal insulins, and provide less glycemic variability. Patients who use these preparations can be continued on these while in the hospital.[26][27] 

For regimens using long-acting insulin, one half of the total daily dose is given as long-acting insulin and one half as rapid-acting insulin. Long-acting insulin should be given once or twice daily. Rapid-acting insulin should be given in divided doses before each meal.[24]

For regimens using intermediate-acting insulin, two-thirds of the total daily dose is given in the morning (further divided into two-thirds NPH insulin and one third fast-acting insulin), and one third in the evening (further divided into half fast-acting with the evening meal and half NPH at bedtime).

The use of sliding scales alone is not recommended, although they may be used on occasion for 24 hours to determine the insulin requirements in some patients.

Consult local protocols for guidance on suitable insulin doses and regimens.

Primary options

insulin aspart: subcutaneously before each meal

or

insulin glulisine: subcutaneously before each meal

or

insulin lispro: subcutaneously before each meal

-- AND --

insulin NPH: subcutaneously twice daily, preferably in the morning and at bedtime

or

insulin glargine: subcutaneously once daily, preferably at bedtime

or

insulin detemir: subcutaneously once daily, preferably at bedtime, or twice daily

or

insulin degludec: subcutaneously once daily

1st line – insulin + treatment of comorbid illness

Back
ACUTE
|
stable noncritical illness: well-controlled known diabetes
|
not eating
1st line – 

insulin + treatment of comorbid illness

For patients who are not taking anything by mouth the ADA recommends an insulin schedule with basal and correction components.[1]

Hypoglycemia should be avoided by regular monitoring of blood glucose and changes in therapy as needed (e.g., reducing insulin).

Consult local protocols for guidance on suitable insulin doses and regimens.

Primary options

insulin NPH: subcutaneously twice daily, preferably in the morning and at bedtime

or

insulin glargine: subcutaneously once daily, preferably at bedtime

or

insulin detemir: subcutaneously once daily, preferably at bedtime, or twice daily

or

insulin degludec: subcutaneously once daily

-- AND --

insulin aspart: subcutaneously before each meal

or

insulin glulisine: subcutaneously before each meal

or

insulin lispro: subcutaneously before each meal

hypoglycemia

1st line – oral carbohydrate + adjustment of diabetic regimen

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ACUTE
|
hypoglycemia
|
able to take orally
1st line – 

oral carbohydrate + adjustment of diabetic regimen

Insulin can induce hypoglycemia leading to neuroglycopenia.

Hypoglycemia is associated with adverse outcomes, especially in intensive care unit patients. Sedation or beta-blockers may mask symptoms of neuroglycopenia, and counter-regulatory responses may be impaired.

Orange juice or oral glucose is given, along with adjustment of regimen (e.g., decrease of insulin dose).

For refractory or severe hypoglycemia, intravenous dextrose or intramuscular glucagon is needed.

2nd line – dextrose or glucagon

Back
ACUTE
|
hypoglycemia
|
able to take orally
2nd line – 

dextrose or glucagon

Insulin can induce hypoglycemia leading to neuroglycopenia.

Hypoglycemia is associated with adverse outcomes, especially in intensive care unit patients. Sedation or beta-blockers may mask symptoms of neuroglycopenia, and counter-regulatory responses may be impaired.

Hypoglycemia should be avoided by regular monitoring of blood glucose and changes in therapy as needed (e.g., reducing an insulin infusion rate promptly).

If hypoglycemia is severe or refractory to oral treatment, dextrose should be given intravenously and blood glucose monitored closely for the next hour. Alternatively, glucagon can be given intramuscularly.

Primary options

dextrose: (50%) 50 mL intravenously as a single dose

OR

glucagon: 1 mg intramuscularly as a single dose, may repeat in 20 minutes as needed

1st line – dextrose or glucagon + adjustment of diabetic regimen

Back
ACUTE
|
hypoglycemia
|
unable to take orally
1st line – 

dextrose or glucagon + adjustment of diabetic regimen

Insulin can induce hypoglycemia leading to neuroglycopenia.

Hypoglycemia is associated with adverse outcomes, especially in intensive care unit patients. Sedation or beta-blockers may mask symptoms of neuroglycopenia, and counter-regulatory responses may be impaired.

Hypoglycemia should be avoided by regular monitoring of blood glucose and changes in therapy as needed (e.g., reducing an insulin infusion rate promptly).

Dextrose should be given intravenously and blood glucose monitored closely for the next hour. Alternatively, glucagon can be given intramuscularly.

Primary options

dextrose: (50%) 50 mL intravenously as a single dose

OR

glucagon: 1 mg intramuscularly as a single dose, may repeat in 20 minutes as needed

preoperative: minor elective surgery

1st line – management of diabetic regimen

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ACUTE
|
preoperative: minor elective surgery
1st line – 

management of diabetic regimen

Patients admitted for minor elective surgery who take oral antidiabetic drugs may continue their oral drugs if the procedure is short and the patient is expected to eat later the same day.

For longer, more complicated procedures, oral drugs are usually discontinued in favor of starting basal-bolus insulin given subcutaneously starting the day of surgery.

While there is little data to inform the timing of discontinuation of glucagon-like peptide-1 (GLP-1) receptor agonists prior to surgery, the American Society of Anesthesiologists (ASA) recommends considering discontinuation of weekly GLP-1 receptor agonists one week before elective surgery due to the risk of pulmonary aspiration of gastric contents.[36] For patients on daily dosing, the advice from the ASA is to consider holding GLP-1 agonists on the day of elective surgery. There is ongoing debate as to whether these recommendations are reasonable.[37]

For patients using insulin before hospitalization, the dose of intermediate-acting insulin is reduced by 30% to 50% the evening before surgery. True basal insulins such as glargine, degludec, or detemir can usually be given at or close to their routine dose. Rapid-acting insulins are held while the patient is not eating.

Long and complicated surgical procedures require intravenous insulin infusion for glucose control and there are a number of algorithms available. In converting stable post-surgical patients from intravenous insulin to subcutaneous basal-bolus regimens, the total daily intravenous dose can be reduced by 20%. Fifty percent of that total is then administered as long-acting insulin once or twice daily, with the other 50% divided into two or three premeal injections.

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Choose a patient group to see our recommendations

Please note that formulations/routes and doses may differ between drug names and brands, drug formularies, or locations. Treatment recommendations are specific to patient groups. See disclaimer

Use of this content is subject to our disclaimer