Assessment of severe hyperglycaemia in adults

For adults who present with severe hyperglycaemia (eg blood glucose concentration more than 20 mmol/L), the priority is to address the symptoms and consequences of hyperglycaemia, including recognition and early management of life-threatening diabetic ketoacidosis or hyperosmolar hyperglycaemia. Some blood glucose meters can test both capillary blood glucose and ketone concentrations. If a suitable meter is not available, a urine dipstick can give clinicians information about hyperglycaemia and the presence of ketones.

Investigate and treat any underlying cause of the hyperglycaemia, such as an acute concurrent stressor (eg infection, cardiovascular event, surgery or other stress) or medications (eg high-dose glucocorticoids); see Glucocorticoid-induced hyperglycaemia.

Note: Treat hyperglycaemia as a medical emergency for any unwell adult.

In an unwell adult, hyperglycaemia should be treated as a medical emergency. If there is any uncertainty about the severity of the patient’s condition, urgently refer them to hospital for expert assessment. A list of indicators for urgent referral in adults presenting with hyperglycaemia is given in Indicators for urgent referral of adults presenting with hyperglycaemia.

Figure 1. Indicators for urgent referral of adults presenting with hyperglycaemia

Urgently refer to hospital adult patients with hyperglycaemia and:

  • signs of ketosis [NB1]
  • strong suspicion of type 1 diabetes, regardless of the degree of hyperglycaemia and even in the absence of ketosis
  • signs of dehydration
  • severe hyperglycaemia in a patient who is vomiting
  • symptoms or signs of an underlying infection
  • altered level of consciousness, confusion or delirium.

If there is any uncertainty about the severity of a patient’s condition, urgently refer the patient to hospital for expert assessment.

Note: NB1: Ketosis can be a sign of severe insulin deficiency. It can present with vomiting, dehydration and sweet smelling (acetone) breath. Blood ketone concentration higher than 1.5 mmol/L may indicate impending diabetic ketoacidosis.