Monitoring Diabetic Ketoacidosis

Limitations of Urine Ketone Testing

Urine ketone tests using nitroprusside reaction only detect acetoacetate (AcAc) and not beta-hydroxybutyrate (bOHB), which is the predominant ketone body in DKA, according to the American Diabetes Association 1, 2
False-positive results can occur with highly colored urine samples, as noted by the American Diabetes Association 1, 3
Positive urine ketone readings can be found in up to 30% of first morning urine specimens from pregnant women, during starvation, and after hypoglycemia, making interpretation challenging, as reported by the American Diabetes Association 1, 3

The American Diabetes Association recommends using blood bOHB levels (preferred cutoff ≥6.3 mmol/L) in combination with evidence of metabolic acidosis (venous pH <7.3 and serum bicarbonate <18 mEq/L) for diagnosis of DKA 7
Specific measurement of blood beta-hydroxybutyrate (bOHB) should be used for diagnosis of DKA and for monitoring during treatment, as suggested by the American Diabetes Association 5, 6
During treatment, monitoring should include blood glucose, electrolytes, BUN, creatinine, venous pH, anion gap, and blood bOHB levels every 2-4 hours, according to the American Diabetes Association 7

In patients with diabetes presenting with typical symptoms and hyperglycemia, positive urine ketone readings only suggest the possibility of impending or established DKA but are not sufficient for diagnosis, as noted by the American Diabetes Association 1
Diagnosis of DKA requires the presence of hyperglycemia, increased blood ketone bodies (particularly bOHB), and acidosis with increased anion gap, according to the American Diabetes Association 1, 7

For patients on SGLT2 inhibitors, which can cause euglycemic DKA, blood ketone monitoring is especially important as these medications can decrease the hyperglycemia typically associated with DKA, as reported by the American Diabetes Association 1

Use blood bOHB measurement as the primary method for diagnosing and monitoring DKA, as recommended by the American Diabetes Association 5, 6
Monitor blood bOHB levels every 2-4 hours during DKA treatment, according to the American Diabetes Association 7
Never rely solely on urine ketone measurements to guide DKA treatment decisions, as suggested by the American Diabetes Association 2, 6