The Correlation of Capillary Blood Ketone Test with Standard Parameters at the Presentation and the Resolution of Pediatric Diabetic Ketoacidosis

Background: The current criteria used to diagnose diabetic ketoacidosis have limitations due to their lack of specificity (bicarbonate and pH) and their qualitative nature (the presence of ketonemia/ketonuria). Currently, there are new techniques that can be used to assess capillary Beta-hydroxybutyrate at the bedside. This method is becoming more popular for diagnosing and treating diabetic ketoacidosis.

Objective: This study aimed to determine the link between the amount of capillary blood ketones and other standard parameters of diabetic ketoacidosis, including pH, venous bicarbonate, carbon dioxide, anion gap, and urine ketones, at the time of diagnosis and resolution.

Study participants and research methodology: A cross-sectional study was conducted on all patients, aged between 1 and 14 years old, who were admitted to the Department of Emergency in the Central Child Teaching Hospital, Baghdad City, Iraq, from March to July 2022. These patients met the diagnostic criteria for diabetic ketoacidosis and also fulfilled the inclusion criteria for this study. The patients were treated in accordance with the 2018 Clinical Practice Consensus Guidelines of the International Society for Pediatric and Adolescent Diabetes for diabetic ketoacidosis. They were monitored until they met the criteria for resolution of diabetic ketoacidosis and were able to tolerate oral fluids without experiencing nausea or vomiting. The capillary blood ketone levels were measured using the bedside eBketone Blood Ketone Monitoring System upon initial presentation and at the time of resolution.

Results: Out of a total of ninety-seven patients with diabetic ketoacidosis, ninety-two patients fulfilled the inclusion criteria for this study. Among them, there were 56 female cases, accounting for 60.9% of the total, and 58 patients were in the pubertal stage, representing 63% of the sample. The average ages of the patients were 9.67± standard deviation (SD) 3.53, with a range of 1-14 years. A total of twenty-five patients were recently diagnosed with type 1 diabetes, accounting for 27.3% of the cases. The acidosis resolved with a median time of 20.42 hours, with a standard deviation of 8.93 hours (range: 8-48 hours). At presentation, this study found that as capillary blood ketone concentrations increased, there was a simultaneous decrease in serum pH, bicarbonate, and carbon dioxide. These changes were statistically significant, with a strong correlation observed between the following parameters: pH (r = −0.493, P = 0.0001), venous bicarbonate (r = - 0.592, P = 0.0001), and carbon dioxide (r = - 0.616, P = 0.0001). At presentation This study found that as capillary blood ketone concentrations increased, there was also an increase in serum Anion gap, urine ketones, and blood glucose. The correlation between these parameters was statistically significant, with the Anion gap having a correlation coefficient of 0.372 (P = 0.0001), urine ketones having a correlation coefficient of 0.671 (P = 0.0001), and blood glucose having a correlation coefficient of 0.207 (P = 0.047).

At Time of Resolution this study found that as capillary blood ketone concentrations decreased, there was an increase in serum pH and bicarbonate levels. The correlation between these parameters was statistically significant: pH (r=-0.305, P= 0.003) bicarbonate (r = -212, P = 0.042). Additionally, during resolution, the study observed a decrease in the Anion gap as capillary blood ketone concentrations decreased, with a statistically significant correlation: Anion gap (r=0.223, P= 0.033). However, there was no significant correlation between capillary blood ketones and both carbon dioxide and urine ketones (r = 0.104, P = 0.325), (r = -0.114, P = 0.279), respectively, at the time of resolution.

Conclusions: Capillary blood ketone measurement shows a stronger correlation with standard parameters of diabetic ketoacidosis compared to urinary ketone measurement. Therefore, capillary blood ketone testing is preferable for early identification and recognition of the resolution of diabetic ketoacidosis episodes.