Metabolic Emergencies

Diagnosis and Management of Inborn Errors of Metabolism in Adult Patients in the Emergency Department

Inborn errors of metabolism (IEM) constitute an important group of conditions characterized by an altered metabolic pathway. There are numerous guidelines for the diagnosis and management of IEMs in the pediatric population but not for adults. Given the increasing frequency of this group of conditions in adulthood, other clinicians in addition to pediatricians should be aware of them and learn to identify their characteristic manifestations. Early recognition and implementation of an appropriate therapeutic approach would improve the clinical outcome of many of these patients. This review presents when and how to investigate a metabolic disorder with the aim of encouraging physicians not to overlook a treatable disorder.

High fever or hypotension predicts non-hypoglycemia in patients with impaired consciousness in prehospital settings

Aim

To evaluate whether vital signs can predict whether hypoglycemia can be eliminated as the cause of impaired consciousness in prehospital settings.

Methods

We extracted the data of patients who underwent blood glucose measurements by paramedics in Kobe City, Japan from April 2015 to March 2019. We used receiver operating characteristic curves and calculated the area under the curve (AUC) to evaluate the validity of the vital signs in distinguishing hypoglycemia. We also calculated stratum-specific likelihood ratios to examine the threshold at which hypoglycemia becomes less likely for each vital sign.

Results

Of the 1,791 patients, 1,242 were eligible for analysis. Hypoglycemia was observed in 324 patients (26.1%). Significant differences in each vital sign were noted between the hypoglycemic and non-hypoglycemic groups. Body temperature was moderately accurate in differentiating between the two groups (AUC, 0.71; 95% confidence interval, 0.68-0.74). Furthermore, in patients with systolic blood pressure <100 mmHg and body temperature ≥38°C, it was unlikely that hypoglycemia caused impaired consciousness (stratum-specific likelihood ratios 0.12 and 0.15; 95% confidence intervals, 0.05-0.25 and 0.06-0.35, respectively).

Conclusion

In the prehospital assessment of patients with impaired consciousness, high fever or hypotension was helpful in differentiating between hypoglycemia and non-hypoglycemia. In particular, body temperature ≥38°C or systolic blood pressure <100 mmHg indicated a low likelihood of hypoglycemia. A validation study is needed to confirm the findings in this study.

Hyponatremia in childhood urinary tract infection

Acute urinary tract infection (UTI) is the most common bacterial infection in childhood. Although hyponatremia was described in ~ 2/3 of these children, its clinical significance is still unclear. Herein, we evaluated the prevalence and clinical implications of hyponatremia in children hospitalized with a UTI. Medical records of previously healthy children hospitalized between January 2011 and December 2016 with UTI were retrospectively reviewed. Patients (median age 5.5 months) were divided into two groups according to their sodium levels: normonatremia (Na ≥ 135 mEq/L) and hyponatremia (Na < 135 mEq/L). Hyponatremia diagnosed on admission was found in 114/219 children (49%). Hyponatremic patients experienced a more severe disease manifested by a longer hospital stay (3.8 vs 3.4 days, p = 0.003), a higher prevalence of abnormal findings on renal ultrasound (10 vs 2, p = 0.01), higher C-reactive protein (CRP) levels (8.6 vs 3.4 mg/dl, p = <0.001), and a negative correlation between sodium levels and CRP (r = - 0.38, p < 0.001).Conclusion:Hyponatremia occurs frequently in children hospitalized with UTI and is associated with elevated inflammatory markers and a more severe disease course. What is Known: • Hyponatremia, one of the most common electrolyte abnormalities, occurs in approximately 1/3 of hospitalized children and in 2/3 of children with pyelonephritis. • In certain cases of various medical conditions, hyponatremia has been shown to correlate with disease severity. What is New: • Hyponatremia in hospitalized children with UTI correlates with elevated inflammatory markers and a more severe disease course.

Inborn Errors of Metabolism in the Emergency Department (Undiagnosed and Management of the Known)

An inborn error of metabolism should be considered in any neonate who presents to the emergency department in extremis and in any young child who presents with altered mental status and vomiting. In children with unknown diagnoses, it is crucial to draw the appropriate laboratory studies before the institution of therapy, although treatment needs rapid institution to mitigate neurologic damage and avoid worsening metabolic crisis. Although there are hundreds of individual genetic disorders, they are roughly placed into groups that present similarly. This article reviews the approach to the patient with unknown metabolic diagnosis and up-to-date management pearls for children with known disorders.

Pediatric critical care

Care of the ill and injured child requires knowledge of unique pediatric anatomic and physiologic differences. Subtleties in presentation and pathophysiologic differences impact management. This article discusses pediatric resuscitation, the presentation and management of common childhood illness, pediatric trauma, and common procedures required in the critically ill child.

Persistent hypoglycemia

Hypoglycemia is a common finding in emergency departments. In this article, we review the causes of hypoglycemia in children, the evaluation and management of a child with persistent hypoglycemia, and causes of adrenal insufficiency in children. We report a case of adrenoleukodystrophy, a type of primary adrenal insufficiency, in a 5-year-old boy who presented with altered mental status, seizures, and hypoglycemia.

Re-occurrence of pancreatic insulinoma: an usual cause of hypoglycaemia

A 42-year-old woman presented to her general practitioner (GP) with episodes of feeling 'shaky' exacerbated by physical exercise and prolonged fast. She was previously diagnosed with an insulinoma in 2006 (serum glucose 1.6 mmol/l, serum insulin 3.1 mIU/l and serum C peptide <165 pmol/l). CT abdomen/transabdominal ultrasound revealed a 1 cm insulinoma in the uncinate process of the pancreas and the patient later underwent pancreatic enucleation in 2006. Postpancreatic enucleation, 72 h fast was negative. The patient remained asymptomatic postoperation and re-presented to a locum GP 6 years later with initial symptoms. She was reviewed during her annual follow-up and, owing to concerns relating to her background, she was admitted to the specialist endocrine department for further investigations. A 72 h fast was positive for hypoglycaemia with serum glucose level 1.8 mmol/l, serum insulin 8.6 mIU/l and serum C peptide 443 pmol/l.

How well does serum bicarbonate concentration predict the venous pH in children being evaluated for diabetic ketoacidosis?

OBJECTIVE

The objective of the study was to determine whether serum bicarbonate (HCO₃) concentration can accurately predict venous pH in the evaluation of diabetic ketoacidosis (DKA).

METHODS

A retrospective review of patients who presented to a children's hospital emergency department and received an International Classification of Diseases, Ninth Revision code related to DKA or diabetes mellitus was performed. To be eligible for inclusion and data abstraction, patients had blood sampled simultaneously for venous blood gas and metabolic panel. A linear regression model was created using pH (dependent variable) and HCO₃ (predictor). The diagnostic performance and accuracy of HCO₃ to discriminate abnormal pH were evaluated using receiver operating characteristic curve analysis.

RESULTS

Three hundred patients met the inclusion criteria. The linear relationship between pH and HCO₃ using the Pearson correlation coefficient was found to be R = 0.89 (confidence interval [CI], 0.83-0.95; R = 0.79). Receiver operating characteristic curve analysis that maximized sensitivity and specificity demonstrated that a HCO₃ 18.5 or less predicts pH less than 7.3 (area under the curve = 0.97; CI, 0.94-0.99; sensitivity, 93%; specificity, 91%), and a HCO₃ 10.5 or less predicts pH less than 7.1 (area under the curve = 0.97; CI, 0.95-0.99; sensitivity, 97%; specificity, 88%).

CONCLUSIONS

Serum bicarbonate accurately predicts abnormal venous pH in children with DKA. Venous pH determination may not be necessary for all patients being evaluated for DKA.

Congenital adrenal hyperplasia: an endocrine disorder with neonatal onset

Congenital adrenal hyperplasia (CAH) is a lifelong endocrine disorder that manifests acutely in the neonatal period. In the affected female newborn, CAH is associated with variable degrees of genital ambiguity that are extremely distressing to the new parents. The manner in which health care professionals react in the delivery room, newborn nursery, or neonatal intensive care unit in the early postnatal period is important. Insensitive or inappropriate statements cannot only be hurtful to families but are long remembered and can shape the attitude formed by parents toward their newborn.

Clinical approach to the diagnoses of inborn errors of metabolism

Inborn errors of metabolism (IEMs) are complex relatively uncommon medical conditions resulting in significant morbidity and mortality. Early recognition and implementation of adequate therapeutic measures are of the utmost importance in minimizing morbidity and improving clinical outcome. This article aims to address the basics of IEMs for familiarizing primary care physicians with different types of metabolic disorders, basic diagnostic strategies, newborn screening programs, and appropriate treatment strategies. Advances in diagnostic and therapeutic options are resulting in increasing longevity and improvement in the clinical outcome of many of these patients.

Endocrine issues in the pediatric intensive care unit

This article reviews selected issues of endocrine concerns in the pediatric intensive care unit, exclusive of diabetic ketoacidosis. The sympathoadrenergic arm of the neuroendocrine stress response is described, followed by discussions of two topics of particular current concern: critical illness hyperglycemia and relative adrenal insufficiency. A selected set of common scenarios encountered in the daily practice of intensive care follows.