Patients with newly discovered hyperglycaemia have significantly higher in-hospital mortality than patients with a known history of diabetes or normoglycaemic patients.
Evidence indicates that the development of hyperglycaemia during acute medical or surgical illness is not a physiological or benign condition, but is a marker of poor clinical outcome and mortality.
Both hyperglycaemia and hypoglycaemia are associated with higher mortality, independent of known history of diabetes.
Effective management of hyperglycaemia is associated with a decreased length of intensive care unit and hospital stay. Tight glycaemic control in the normal range of 4.4 to 6.1 mmol/L (80-110 mg/dL) 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 hospital who are not critically ill. Sliding scale insulin alone should not be used in these patients.
Inpatient glycaemic management refers to identifying and treating hyperglycaemia in the setting of acute illness in hospitalised patients with either pre-existing diabetes or new-onset hyperglycaemia. 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 hospital: in these cases patients are not aware they have diabetes but present with hyperglycaemia, and diabetes is diagnosed subsequently, 3) transient hyperglycaemia: 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 hypoglycaemia in the inpatient setting is also addressed. Diabetic ketoacidosis and non-ketotic hyperosmolar hyperglycaemia are not specifically addressed.
History and exam
Key diagnostic factors
- presence of risk factors for hyperglycaemia
- presence of risk factors for hypoglycaemia
- history of diabetes mellitus
- severe intercurrent illness or infection (hyperglycemia)
- insulin use (hypoglycemia)
- reduced level of consciousness/coma (hypoglycaemia and hyperglycaemia)
- sweating (hypoglycaemia)
- tachycardia (hypoglycaemia)
- unusual behaviour (hypoglycaemia)
Other diagnostic factors
- history of recent corticosteroid use
- signs of diabetic retinopathy
- signs of diabetic neuropathy
- polyuria, polydipsia, or unintentional weight loss
- severe illness (hyperglycaemia or hypoglycaemia)
- corticosteroid use (hyperglycaemia)
- poorly controlled diabetes mellitus (hyperglycaemia)
- insulin administration or insulin secretagogues (hypoglycaemia)
- changes to corticosteroid or insulin regimen (hypoglycaemia or hyperglycaemia)
- poor nutritional intake (hypoglycaemia)
- older age or cognitive impairment (hypoglycaemia)
1st investigations to order
- random plasma glucose
- serum urea, 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: hyperglycaemia
stable non-critical illness: uncontrolled hyperglycaemia
stable non-critical illness: well-controlled known diabetes
preoperative: minor elective surgery
- Transient hyperglycaemia (e.g., from stress, corticosteroids, parenteral/enteral nutrition)
- Type 1 diabetes mellitus
- Type 2 diabetes mellitus
- Standards of medical care in diabetes - 2022
- Management of hyperglycemia in hospitalized patients in non-critical care settings
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