Aim: To assess the utility of near patient blood ketone measurements in predicting diabetic ketoacidosis (DKA) among a group of hyperglycaemic unwell patients presenting to a hospital emergency department.
Methods: Near patient blood beta-hydroxybutyrate (beta-OHB) testing has recently been introduced as a new tool in our hospital Accident and Emergency department (A&E) for patients with a finger-prick glucose of > 11 mmol/l. We reviewed the records of the first 50 patients to have a beta-OHB measurement to establish if they developed DKA or received treatment with intravenous insulin within 48 h of presentation. We then compared the diagnostic power of beta-OHB measurements with other clinical, physiological and biochemical markers of DKA.
Results: Nine patients had DKA, eight had a compensated metabolic acidosis secondary to raised serum ketones, and 33 had no evidence of DKA during the following 48 h. The median (range) beta-OHB levels in each group were 6.0 (3.1-6.0) mmol/l, 3.4 (1.2-5.7) mmol/l, and 0.1 (0.0-1.2) mmol/l, respectively. A beta-OHB level of > or = 3.0 mmol/l had a sensitivity of 100% and specificity of 88% for DKA. All those with beta-OHB level > 3.0 mmol/l required treatment with intravenous insulin.
Conclusion: Measuring beta-OHB when a hyperglycaemic patient is identified could offer a simple method of identifying at an early stage those patients at highest risk of DKA (beta-OHB > 3.0 mmol/l), and redirecting the search for a diagnosis in others (beta-OHB < 1.0 mmol/l).