Introduction to hyperglycaemia and diabetes in hospitalised adults

Hyperglycaemia in hospitalised adults is associated with increased morbidity and a higher mortality rate. Avoiding severe hyperglycaemia is important; however, avoiding hypoglycaemia is also crucial. Many hospitals have protocols to standardise approaches for inpatient management of hyperglycaemia and diabetes; follow local protocols if available.

In general, the target blood glucose concentrations should be between 5 to 10 mmol/L; aiming for tighter targets than this increases the occurrence of hypoglycaemia and increases mortality in critically ill patients. Higher blood glucose concentrations may be acceptable in patients with life-limiting illness or in those with major comorbidities (see Glycaemic targets for adults with type 2 diabetes).

All hospitalised adults with diabetes or hyperglycaemia should have a glycated haemoglobin (HbA1c) test performed in hospital unless one has been done in the last 3 months. The prevalence of diabetes among hospitalised adults is about three times that in the community, and diabetes is undiagnosed in about 10% of hospitalised adults.

Chronic complications of diabetes should be considered in all hospitalised adults with diabetes, even in patients newly diagnosed because diabetes may have been present for some time before diagnosis (see Overview of diabetes complications). Kidney function should be checked and feet routinely examined. Peripheral neuropathy and peripheral vascular disease put patients at higher risk of foot complications while in hospital (eg pressure ulcers).

Hospitalised adults without pre-existing diabetes who have hyperglycaemia in hospital should have definitive diagnostic testing for diabetes performed when they are well (see Tests to diagnose diabetes). Liaison with their general practitioner is important.