Point-of-care test identifies diabetic ketoacidosis at triage. - Diabetic Ketoacidosis Diagnosis and Tests

Point-of-care test identifies diabetic ketoacidosis at triage.
2006 May 11.
Naunheim R, Jang TJ, Banet G, Richmond A, McGill J.
Department of Emergency Medicine, Washington University, St. Louis, MO, USA.
Acad Emerg Med. 2006

BACKGROUND: Diabetic ketoacidosis (DKA) is a common, life-threatening complication of diabetes. The diagnosis of DKA relies on signs and symptoms, plus laboratory findings of blood glucose (BG) of > 250 mg/dL, an anion gap (AG) of > or = 15 mmol/L, and carbon dioxide (CO2) of < or = 18 mmol/L when other causes of acidosis are excluded. OBJECTIVES: To compare the results of a point-of-care test for the ketone beta-hydroxybutyrate (beta-OHB) with standard measures for accuracy in predicting DKA. METHODS: After providing informed consent, 160 patients who presented with BG of > 250 mg/dL underwent testing for beta-OHB with the Precision Xtra meter (Abbott Laboratories, North Chicago, IL) at triage in a large urban hospital emergency department. The diagnosis of DKA was made by clinicians by using standard clinical criteria without knowledge of the beta-OHB test. RESULTS: A diagnosis of DKA was made in 57 of 160 subjects. The beta-OHB values correlated strongly with AG (r = 0.66, p < 0.001) and with CO2 (r = -0.69, p < 0.001), as well as with glucose (r = 0.31, p < 0.001). Cross-classification of DKA vs. beta-OHB yielded sensitivity of 98% (95% CI = 91% to 100%), specificity of 85% (95% CI = 78% to 91%), with a positive likelihood ratio of 6.7 (95% CI = 4.22 to 10.78), and negative likelihood ratio of 0.021 (95% CI = 0.003 to 0.144) at the manufacturer-suggested beta-OHB level of 1.5. CONCLUSIONS: The point-of-care test for beta-OHB was as sensitive as more established indicators of DKA. It is more useful than glucose alone for the diagnosis of DKA and offers immediate diagnosis of patients at triage.