Ketone monitoring

Elevated ketone concentrations in blood or urine may be an indication of impending diabetic ketoacidosis (DKA) in patients with type 1 diabetes; prompt action may avert a crisis.

Check for elevated ketones:

during an acute illness or stress
when blood glucose concentrations are consistently higher than 15 mmol/L
when any symptoms of ketoacidosis (eg nausea, vomiting, abdominal pain) are present.

A blood ketone concentration more than 1.5 mmol/L indicates the potential for development of DKA. Seek urgent expert advice or refer to hospital (see also Diabetic ketoacidosis).

For advice about the approach to early mild ketosis (ie blood ketone concentration 0.6 to 1.5 mmol/L), see Sick-day management for adults with type 1 diabetes.

All patients with type 1 diabetes should have access to a blood glucose meter that can measure blood ketone concentrations.

If a suitable blood glucose meter is not available to check for ketones, urine ketone strips can be used; however, a strong clinical suspicion of ketoacidosis with a negative urine ketone result should still prompt further assessment.

Note: A strong clinical suspicion of ketoacidosis with a negative urine ketone result still warrants prompt intervention.

Beta-hydroxybutyrate is the predominant ketone body produced in DKA, but urine ketone strips only detect the ketone acetoacetate, which sometimes gives false-negative results. False-negative results are also possible when ketone strips have been stored incorrectly (ie are exposed to air for an extended period of time) or are out of date.