Exploring the clinical utility of blood ketone levels in the emergency department assessment of paediatric patients

Clinical significance of an elevated on-admission beta-hydroxybutyrate in acutely ill adult patients without diabetes

OBJECTIVE

To determine the relationship between point-of-care β-hydroxybutyrate (BHB) concentration and outcomes in adult patients without diabetes admitted through ED.

METHODS

This was a prospective study from 10 March to 2 July 2021. Admitted patients without diabetes had capillary BHB sampled in ED. Outcomes of length-of-stay (LOS), composite mortality/ICU admission rates and clinical severity scores (Quick Sepsis Organ Failure Assessment score/National Early Warning Score [qSOFA/NEWS]) were measured. BHB was assessed as a continuous variable and between those with BHB above and equal to 1.0 mmol/L and those below 1.0 mmol/L.

RESULTS

A total of 311 patients were included from 2377 admissions. Median length-of-stay was 4.1 days (IQR 2.1-9.8), 18 (5.8%) died and 37 (11.8%) were admitted to ICU. Median BHB was 0.2 mmol/L (IQR 0.1-0.4). Twenty-five patients had BHB ≥1.0 mmol/L and five were >3.0 mmol/L. There was no significant difference in median LOS for patients with BHB ≥1.0 mmol/L compared to non-ketotic patients, 5.3 days (IQR 2.2-7.5) versus 4.1 days, respectively (IQR 2.0-9.8) (P = 0.69). BHB did not correlate with LOS (Spearman ρ = 0.116, 95% confidence interval: 0.006-0.223). qSOFA and NEWS also did not differ between these cohorts. For those 25 patients with BHB ≥1.0 mmol/L, an infective/inflammatory diagnosis was present in 11 (44%), at least 2 days of fasting in 10 (40%) and ethanol intake >40 g within 48 h in 4 (16%).

CONCLUSIONS

Routine BHB measurement in patients without diabetes does not add to clinical bedside assessment and use should be limited to when required to confirm a clinical impression.

What is the utility of blood beta-hydroxybutyrate measurements in emergency department in patients without diabetes: a systematic review

BACKGROUND

Ketones are synthesised as an alternative fuel source during times of energy restriction. In the absence of a hyperglycemic emergency, ketosis in patients presenting to the emergency department (ED) may indicate reduced carbohydrate intake. In the perioperative setting, excess fasting with ketosis is associated with worse outcomes; however, whether ketosis in patients without diabetes presenting to ED is also associated with worse outcomes is unclear. This systematic review aims to examine the evidence for ketosis in predicting the need for hospital admission in patients without diabetes, presenting to the ED.

METHODS

A systematic review was performed using PRISMA guidelines. We searched electronic bases (OVID-Medline, OVID-EMBASE, Scopus and PubMed) up to December 2022. Eligible studies included children or adults without diabetes presenting to the ED where a point-of-care capillary beta-hydroxybutyrate (BHB) was measured and compared to outcomes including the need for admission. Outcome measures included need for admission and length of stay. Content analysis was performed systematically; bias and certainty assessed using standard tools.

RESULTS

The literature search found 17,133 citations, 14,965 papers were subjected to title and abstract screening. The full text of 62 eligible studies were reviewed. Seven articles met the inclusion criteria. Six studies were conducted solely in the paediatric population, and of these, four were limited to children presenting with gastroenteritis symptoms. Median BHB was higher in children requiring hospital admission with an AUC of 0.64-0.65 across two studies. There was a weak correlation between BHB and dehydration score or duration of symptoms. The single study in adults, limited to stroke presentations, observed no relationship between BHB and neurological deficit at presentation. All studies were at risk of bias using the Newcastle-Ottawa Scale and was assessed of "very low" to "low" quality due to their study design in the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Heterogeneity amongst selected studies precluded meta-analysis.

CONCLUSION

The evidence for any utility of BHB measurement in the ED in absence of diabetes is limited to the paediatric population, specifically children presenting with symptoms of gastroenteritis. Any role in adults remains unexplored.

Starvation Ketosis in the Pediatric Emergency Department: A Prospective Estimate of Prevalence

OBJECTIVES

Starvation ketosis may occur in children during intercurrent illnesses due to metabolic adaptation to fasting, resulting in significant ketonemia and sometimes ketoacidosis. Also known as accelerated starvation, common symptoms are vomiting, lethargy, and seizures. Previous studies found the prevalence of ketotic hypoglycemia to be 4 per 100,000 presentations to the emergency department (ED). We hypothesized that the prevalence had been underestimated due to the retrospective nature and restricted definitions of previous studies. Our aim was to determine if a prospective study would confirm a higher prevalence of starvation ketosis in pediatric patients presenting to the ED.

METHODS

A prospective observational study of consecutive patients was performed in an urban pediatric ED utilizing point-of-care testing of capillary blood glucose and ketones in symptomatic children.

RESULTS

This study found the prevalence of clinically significant ketosis (defined as beta-hydroxybutyrate 2.5 mmol/L or more) to be approximately 1800 per 100,000 ED presentations, with more than 170 per 100,000 also being hypoglycemic. Affected patients were 3 months to 9 years of age. Fifty-five percent of the presentations were boys, and 56% were under the 50th centile for weight.

CONCLUSIONS

This prospective observational study using a targeted testing regimen found the prevalence of both starvation ketosis and hypoglycemia to be much greater than previous studies which used retrospective analyses. A simple capillary test for ketones should be considered in unwell children younger than 10 years who present with vomiting or lethargy, as this may identify the need for specific therapy to resolve ketosis.

The utility of ketones at triage: a prospective cohort study

OBJECTIVE

To establish the relationship between serum point-of-care (POC) ketones at triage and moderate-to-severe dehydration based on the validated Gorelick Scales.

DESIGN, SETTING AND PATIENTS

Prospective unblinded study from April 2016 to February 2017 in a paediatric emergency department. Patients aged 1 month to 5 years, with vomiting and/or diarrhoea and/or decreased intake with signs of moderate or severe dehydration or clinical concern for hypoglycaemia were eligible.

MAIN OUTCOME MEASURES

The primary outcome was to describe the relationship between triage POC ketones to the two Gorelick Scales. Secondary outcomes were to examine the response of ketone levels to fluid/glucose administration and patient disposition.

RESULTS

One-hundred and ninety-eight patients were included; median age 1.8 years. The median triage ketones were 4.6 (IQR 2.8-5.6) mmol/L. A weak correlation was identified between triage ketones and the 10-point Gorelick Scale (Spearman's ρ=0.217, p=0.002), however no correlation between triage ketones and the 4-point Gorelick Scale was identified. Those admitted had median triage ketones of 5.2 (IQR 4-6) mmol/L and repeat ketones of 4.6 (IQR 3.3-5.7) mmol/L compared with 4.2 (IQR 2.4-5.3) mmol/L and 2.9 (IQR 1.6-4.2) mmol/L in those discharged home.

CONCLUSION

No correlation between triage POC ketones and the 4-point Gorelick Scale was established. POC ketones at triage have poor accuracy for predicting hospital admission. The elevated profile of POC ketones in non-diabetic children with acute illness suggests a potential target of tailored treatments for further research.

Review article: Accelerated starvation of childhood: Have I judged ketones?

Acute ketosis is an important physiological mechanism to prevent irreversible neurological damage from hypoglycaemia during starvation, and represents a significant metabolic stress. A cohort of children adapt to relatively short periods of reduced caloric intake by generating large quantities of ketone bodies. When excessive, the gastrointestinal symptoms of starvation ketosis such as nausea and pain may create a vicious cycle that delays spontaneous resolution. The presence of ketones can be dismissed as a normal feature of childhood metabolism, sometimes even when extreme. A broader understanding of this process under the banner of 'accelerated starvation of childhood' is helpful for clinicians managing acute illness in children. We advocate that children less than 7 years of age with a history suggestive of accelerated starvation of childhood should be screened by emergency clinicians for ketosis using a simple and cheap bedside capillary test, even if glucose levels are greater than 2.6 mmol/L. Identification and appropriate management of ketosis may alleviate the distressing gastrointestinal symptoms associated with many minor illnesses, and potentially prevent hypoglycaemia in some children. Appropriate advice to carers may be helpful to prevent further episodes. Illustrative case examples from our own practice are provided.

The Significance of an Increased Beta-Hydroxybutyrate at Presentation to the Emergency Department in Patients with Diabetes in the Absence of a Hyperglycemic Emergency

The significance of hyperketonemia in adults with diabetes presenting to the emergency department with acute illness, not due to a diabetic hyperglycemic emergency, has not been well characterized. Adult patients with diabetes presenting to the emergency department who had venous blood gas and beta-hydroxybutyrate levels measured whilst in the emergency department were retrospectively evaluated for the relationship between BHB and clinical outcomes. Over 6 months, 404 patients with diabetes had at least one beta-hydroxybutyrate level measured in the emergency department. There were 23 admissions for diabetic ketoacidosis (DKA) or hyperosmolar state. Of the remainder, 58 patients had a beta-hydroxybutyrate ≥ 1 mmol/L; this group had a higher glucose at presentation (19.0 (8.8) versus 10.4 (9.9) mmol/L), higher HbA1c (8.8 (5.4) versus 8.0 (3.3)%), lower bicarbonate (22.6 (6.2) versus 24.8 (4.7) mmol/L), and higher anion gap (14.8 (6.1) versus 12.6 (4.2)) than had those with BHB < 1 mmol/L. There was no association between the presence of ketosis and the length of stay (4.2 (7.3) versus (3.0) (7.2) days). Acute illness in those with diabetes associated with ketosis in the absence of DKA is associated with worse glycaemic control than in those without ketosis. Ketosis may represent an intermediate state of metabolic dysregulation rather than being associated with a more severe acute illness, as suggested by no relationship between BHB and length of stay.

Inborn Errors of Metabolism

Inborn errors of metabolism are single gene disorders resulting from the defects in the biochemical pathways of the body. Although these disorders are individually rare, collectively they account for a significant portion of childhood disability and deaths. Most of the disorders are inherited as autosomal recessive whereas autosomal dominant and X-linked disorders are also present. The clinical signs and symptoms arise from the accumulation of the toxic substrate, deficiency of the product, or both. Depending on the residual activity of the deficient enzyme, the initiation of the clinical picture may vary starting from the newborn period up until adulthood. Hundreds of disorders have been described until now and there has been a considerable clinical overlap between certain inborn errors. Resulting from this fact, the definite diagnosis of inborn errors depends on enzyme assays or genetic tests. Especially during the recent years, significant achievements have been gained for the biochemical and genetic diagnosis of inborn errors. Techniques such as tandem mass spectrometry and gas chromatography for biochemical diagnosis and microarrays and next-generation sequencing for the genetic diagnosis have enabled rapid and accurate diagnosis. The achievements for the diagnosis also enabled newborn screening and prenatal diagnosis. Parallel to the development the diagnostic methods; significant progress has also been obtained for the treatment. Treatment approaches such as special diets, enzyme replacement therapy, substrate inhibition, and organ transplantation have been widely used. It is obvious that by the help of the preclinical and clinical research carried out for inborn errors, better diagnostic methods and better treatment approaches will high likely be available.

Predictors of outcomes in pediatric enteritis: a prospective cohort study

OBJECTIVES

Oral rehydration therapy is underused by physicians treating children with acute infectious enteritis. To guide management, we hypothesized that clinical variables available at the initial assessment could be identified that will predict the need for intravenous fluid administration.

PATIENTS AND METHODS

Clinical data were prospectively collected on a cohort of 214 children, aged 6 months to 10 years, treated in an emergency department for dehydration secondary to acute enteritis. All of the children performed supervised oral rehydration therapy for a minimum of 60 minutes according to protocol.Outcomes assessed were intravenous rehydration, return visits after discharge, and successful oral rehydration therapy. The latter variable was defined as the consumption of > or = 12.5 mL/kg per hour of oral rehydration solution. Variables individually associated with outcomes of interest were evaluated by using multiple logistic regression analysis.

RESULTS

Forty-eight (22%) of 214 children received intravenous rehydration. In multivariate analysis, the 2 clinical predictors of intravenous rehydration were large urinary ketones and altered mental status. Significant predictors of repeat emergency department visits within 3 days included > or = 10 episodes of vomiting over the 24 hours before presentation and a higher heart rate at discharge from the emergency department.

CONCLUSIONS

Among children with enteritis and mild-to-moderate dehydration, the presence of large urine ketones or an altered mental status is associated with intravenous rehydration after a 60-minute oral rehydration therapy period. Caution should be exercised before discharging children with either tachycardia or a history of significant vomiting before presentation, because they are more likely to require future emergency department care.