Capillary β – Hydroxybuterate testing in patients with diabetic ketoacidosis

Abstract

Introduction: Diabetic ketoacidosis (DKA) is a major life-threatening complication of both type 1 and type 2 diabetes. Insulin treatment for diabetic ketoacidosis is guided using the changes in blood glucose levels, blood gas analysis and urine ketone measurement. Evidence for the use of capillary β -Hydroxybuterate in the monitoring of therapy for diabetic ketoacidosis is not sufficient, and needs to be evaluated in adult patients. The present study was undertaken to determine if quantitative measurement of β- Hydroxybuterate can simplify the management of diabetic ketoacidosis, and if the correction of hyperketonaemia could predict resolution of diabetic ketoacidosis. Methods: A prospective, descriptive study, evaluating measurement of capillary β-Hydroxybuterate in patients with diabetic ketoacidosis was performed. The relationship between capillary β-Hydroxybuterate levels and values of pH was assessed during treatment and as a possible end point evaluation for intravenous insulin therapy. Patients were recruited at two hospitals over a 24 month period. All patients were treated according to a standard DKA management protocol. Data was collected until resolution of DKA and all patients were followed up until discharge. Results: 54 patients were included in the analysis. The mean age of included patients was 36.4 years (SD 10.32). The relationship between capillary ketones, (β - hydroxybuterate) and pH was explored using non- linear mixed models, fitted with restricted cubic splines. The results from this analysis suggest a complex, time dependant association between pH and measured β - Hydroxybuterate. Assessing if β-Hydroxybuterate could predict normalisation of pH, was done with logistic regression (with subject-specific intercept and slope) including restricted cubic splines. From this model it is evident that the cut-off values for resolution, using capillary ketones, is definitely time dependent. Conclusion: This study did not show to a clinically significant, applicable relationship between capillary β-Hydroxybuterate levels and values of pH during treatment of DKA. A single cut-off value for DKA resolution could not be determined, suggesting that β-Hydroxybuterate capillary measurement alone cannot be used as a possible end point evaluation for intravenous insulin therapy.