Patients with newly discovered hyperglycemia have significantly higher in-hospital mortality than patients with a known history of diabetes or normoglycemic patients.
Evidence indicates that the development of hyperglycemia during acute medical or surgical illness is not a physiologic or benign condition, but is a marker of poor clinical outcome and mortality.
Both hyperglycemia and hypoglycemia are associated with higher mortality, independent of known history of diabetes.
Effective management of hyperglycemia is associated with a decreased length of intensive care unit and hospital stay. Tight glycemic control in the normal range of 80-110 mg/dL (4.4 to 6.1 mmol/L) may not be necessary, however, and may in fact be harmful.
A basal-bolus insulin regimen or a basal insulin regimen may be used in patients admitted to the hospital who are not critically ill. Sliding scale insulin alone should not be used in these patients.
Inpatient glycemic management refers to identifying and treating hyperglycemia in the setting of acute illness in hospitalized patients with either pre-existing diabetes or new-onset hyperglycemia. This may occur in the intensive care unit or in the general ward, and evidence and guidelines differ between these settings. The three groups of patients to consider are the following: 1) known diabetes mellitus before admission, 2) new diagnosis of diabetes mellitus made on admission to the hospital: in these cases patients are not aware they have diabetes but present with hyperglycemia, and diabetes is diagnosed subsequently, 3) transient hyperglycemia: this may be related to stress, drug therapy such as corticosteroids, or parenteral and enteral nutrition, and resolves when the inciting factor is removed.
The prevention and management of hypoglycemia in the inpatient setting is also addressed. Diabetic ketoacidosis and non-ketotic hyperosmolar hyperglycemia are not specifically addressed.
History and exam
Key diagnostic factors
- history of diabetes mellitus
- severe intercurrent illness or infection (hyperglycemia)
- insulin use (hypoglycemia)
- reduced level of consciousness/coma (hypoglycemia and hyperglycemia)
- sweating (hypoglycemia)
- tachycardia (hypoglycemia)
- unusual behavior (hypoglycemia)
Other diagnostic factors
- history of recent corticosteroid use
- signs of diabetic retinopathy
- signs of diabetic neuropathy
- polyuria, polydipsia, or unintentional weight loss
- severe illness (hyperglycemia or hypoglycemia)
- corticosteroid use (hyperglycemia)
- poorly controlled diabetes mellitus (hyperglycemia)
- insulin administration or insulin secretagogues (hypoglycemia)
- changes to corticosteroid or insulin regimen (hypoglycemia or hyperglycemia)
- poor nutritional intake (hypoglycemia)
- older age or cognitive impairment (hypoglycemia)
1st investigations to order
- random plasma glucose
- serum BUN, creatinine, and GFR calculation
- spot urine albumin/creatinine ratio
- serum ketones
Investigations to consider
- post-discharge fasting plasma glucose or HbA1c
- post-discharge oral glucose tolerance test
critically ill or unplanned surgery or in ICU: hyperglycemia
stable noncritical illness: uncontrolled hyperglycemia
stable noncritical illness: well-controlled known diabetes
preoperative: minor elective surgery
- Transient hyperglycemia (e.g., from stress, corticosteroids, parenteral/enteral nutrition)
- Type 1 diabetes mellitus
- Type 2 diabetes mellitus
- Standards of care in diabetes - 2023
- Management of hyperglycemia in hospitalized patients in non-critical care settings
Diabetes: what is it?
Diabetes type 2: should I take insulin?More Patient leaflets
- Log in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer