Use of beta-hydroxybutyric acid levels in the emergency department

Implementation of a "hypoglycemia kit" in a pediatric emergency room: A retrospective study during 2011-2019

INTRODUCTION

Hypoglycemia is a common symptom in pediatrics that can lead to neurological sequelae. The etiologies are mostly benign, but hypoglycemia can be a symptom of severe underlying disease. To streamline the etiological investigations, a "hypoglycemia kit," containing supplies needed to perform specific analyses quickly, was made available in the pediatric emergency department of the Rouen University Hospital in 2011. Since its introduction, this kit has been used to explore all cases of hypoglycemia regardless of the context. However, although very useful, these analyses are expensive. The objective of our study was to examine the cost-effectiveness of this kit and to refine its indications if necessary.

METHODS

This was a non-interventional and retrospective single-center study. Digital records of patients for whom a hypoglycemia kit was used from September 2011 to August 2019 at the pediatric emergency department of Rouen University Hospital were used to retrieve clinical characteristics, laboratory results, and the causes of hypoglycemia.

RESULTS

The study included 82 patients. The etiologic investigation concluded that 74 patients had functional hypoglycemia, and eight cases were attributed to other etiologies. In two cases, the kit led to a diagnosis, i.e., 2.4 % efficiency. A history of congenital malformations or previous hypoglycemia was significantly associated with severe etiologies. However, there was no significant association between hypoglycemia severity, age, sex, and these etiologies.

CONCLUSION

Our study reveals that the cost-effectiveness of the hypoglycemia kit is low in pediatric emergencies (2.4 %) at Rouen University Hospital, where functional hypoglycemia remains the leading cause of hypoglycemia. However, our results allow us to suggest a decision tree for refining the usability of this kit, which would considerably increase its efficiency.

Urinary acetoacetate or capillary ??-hydroxybutyrate for the diagnosis of ketoacidosis in the Emergency Department setting

OBJECTIVES

We compared the semiquantitative measurement of acetoacetate using urinary dipsticks with the bedside quantitative fingerprick measurement of the principal ketone bodies 3-beta-hydroxybutyrate, for the diagnosis of ketoacidosis.

METHODS

This is a one year retrospective study of patients who presented with hyperglycemia levels of 250 mg/l or greater in the Emergency Department setting. We compared the sensitivity, specificity, and predictive value of ketonuria and ketonemia for the diagnosis of ketoacidosis (urine or blood ketone bodies, blood bicarbonates <20 mmol/l, anion gap >16 meq/l) in a sample of patients for whom the levels of ketone bodies in the blood and urine as well as serum electrolytes were available.

RESULTS

We studied 355 hyperglycemic patients. The median time between arrival and dipstick testing was 21 min, and was greater than 2 h in more than 10% of cases. Comparison between ketonuria and ketonemia was performed in 173 patients (6% with diabetic ketoacidosis). Ketonuria equal to or less than one cross or a 3-beta-hydroxybutyrate value lower than 3 mmol/l enabled ketoacidosis to be excluded (negative predictive value 100%). At two-cross cutoff points for ketonuria and at the 3 mmol/l cutoff point for ketonemia, the two tests had the same sensitivity (100%), but the specificity of 3-beta-hydroxybutyrate (94%) was significantly higher (P<0.0001) than that of ketonuria (77%). The best positive predictive value for ketonemia was obtained at the 5 mmol/l cutoff point (100%) and for ketonuria at the three-cross cutoff point (26%). At the three-cross cutoff point for ketonuria and at the 5 mmol/l cutoff point for ketonemia, the two tests had the same negative likelihood ratio (0.1), but the positive likelihood ratio of 3-beta-hydroxybutyrate (infinite) was higher than that of ketonuria.

CONCLUSION

The measurement of 3-beta-hydroxybutyrate in capillary blood is faster and more effective than the use of dipsticks in the urine to detect ketoacidosis in the Emergency Department setting.

Evaluation of a bedside blood ketone sensor: the effects of acidosis, hyperglycaemia and acetoacetate on sensor performance

AIMS

To assess the performance of a handheld bedside ketone sensor in the face of likely metabolic disturbances in diabetic ketoacidosis, namely: pH, glucose and acetoacetate.

METHODS

The effects of pH (7.44-6.83), glucose (5-50 mmol/l) and acetoacetate (0-5 mmol/l) were examined in venous blood to investigate the accuracy of betahydroxybutyrate measurement (0-5 mmol/l) by a handheld ketone sensor. Sensor results were compared with a reference method. Linear regression models were fitted to the difference between the methods with the concentration of metabolite as the explanatory factor.

RESULTS

Decreasing pH and increasing glucose had no effect on the accuracy of the handheld ketone sensor; the gradients of the fitted lines were -0.14 and -0.003, respectively. The 95% confidence intervals were -0.7-0.4 and -0.01-0.004, respectively (P = 0.59 and 0.4, respectively). In the acetoacetate study, a positive relationship between the sensor and reference method results was found, the gradient was 0.09. The 95% confidence interval was 0.05-0.14 (P < or = 0.001), indicating that high concentrations of acetoacetate interfere with the sensor performance.

CONCLUSIONS

Acidosis and hyperglycaemia have minimal effects on the sensor performance. However, high concentrations of acetoacetate result in some overestimation of betahydroxybutyrate. This bedside ketone sensor provides useful data over a broad range of conditions likely to be encountered during moderate to severe diabetic ketoacidosis.