Hypoglycemia
Objectives
Upon finishing this module, the student will be able to:
- Review the signs and symptoms associated with hypoglycemia in infants and children.
- Review the appropriate laboratory evaluation of a patient with hypoglycemia.
- Review the methods of treatment of a pediatric patient with hypoglycemia.
Contributors
Update Author: Timothy Brenkert, MD, RDMS.
Original Authors: Kenny Banh, MD; and Jason Tsukamaki, MD.
Update Editor: Erica R. Tabakin, MD.
Original Editor: David A. Wald.
Last Updated: 2024
Introduction
Hypoglycemia is an important and easily reversible cause of altered mental status in patients presenting to the emergency department (ED). In patients with type 1 diabetes, hypoglycemia is a common occurrence, though there is evidence that the amount of time these patients spend in a hypoglycemic state and the rates of severe hypoglycemia have declined in recent years with insulin pumps and continuous glucose monitors. Excluding this group, almost all hypoglycemia in children occurs during periods of decreased or absent oral intake, often coupled with increased energy demand. Uniquely within the pediatric population, an underlying inborn error of metabolism should also be considered when evaluating a patient presenting with new hypoglycemia. While there is no universally accepted blood glucose value, hypoglycemia is generally defined as a plasma glucose concentration low enough to result in symptoms such as altered mental status. This typically occurs at blood glucose levels less than 60 mg/dL, though the blood glucose level at which a patient may become symptomatic is highly variable. Additionally, the patient’s ability to detect and/or convey such symptoms also varies within the pediatric population. Ultimately, a serum glucose level of less than 40 mg/dL in neonates and less than 50 mg/dL in all other age groups should be considered abnormally low.
The signs and symptoms of hypoglycemia are nonspecific and are often overlooked, particularly in the infant and young child. Hypoglycemia should be considered in the differential diagnosis for all patients with altered mental status (including those in the pre-hospital setting) and in any patients presenting with a seizure. This condition is easily and rapidly identified with bedside glucometers, and can be quickly treated with intravenous dextrose if a high index of suspicion of its presence is maintained. A patient presenting with hypoglycemia can easily be misdiagnosed as a seizure or post-ictal state, stroke, psychosis, drug ingestion, or a traumatic head injury if the blood glucose level is not obtained. Failure to determine blood glucose levels early in the evaluation process can lead to a missed diagnosis and can be associated with progressive CNS dysfunction, cardiac dysrhythmias, or even death. In children, long-term consequences of these episodes can include developmental delays as well as physical and learning disabilities.
Obtaining an accurate medical history in a patient with an altered mental status can be difficult, however, it is very important as it is critical to try to establish a cause for the hypoglycemia. Because hypoglycemia in children often occurs after a period of fasting, a careful dietary history of the prior 24 hours should be elicited. The possibility of a toxic ingestion should also be considered as ethanol, beta-blockers, insulin and oral hypoglycemic agents (sulfonylureas) are commonly found in homes and could lead to life threatening hypoglycemia. It is also important to screen for infectious symptoms as infections can cause hypoglycemia. Family history should be explored as well for evidence of an undiagnosed metabolic disorder.
Glucose is the main substrate for CNS function and therefore most hypoglycemic episodes include neurologic dysfunction, manifested by:
- Altered level of consciousness.
- Agitation, combativeness, or irritability.
- Confusion or lethargy.
- Seizures or focal neurologic deficits.
As blood glucose levels fall, counter-regulatory hormones are released (mainly catecholamines), resulting in activation of the sympathetic nervous system. Findings may include diaphoresis, nausea and/or vomiting, nervousness or anxiety, palpitations or tachycardia, and tremors.
Infants and toddlers frequently exhibit more nonspecific symptoms such as irritability, lethargy, poor feeding, cyanosis, and tremors or jitteriness. Commonly, infants may present with a hypoglycemic seizure without having manifested any prior symptoms.
Point of Care Gluocse Testing
This is the preferred method to obtain blood glucose levels as the results are immediately available. The accuracy of bedside glucose testing is less reliable at extremely high and low glucose levels, so these values may need confirmation by laboratory analysis. If possible, additional blood should be drawn prior to treatment for chemical (ß-hydroxybutyrate, acetoacetate, amino acid profile, acylcarnitine profile), toxicologic, and hormonal (insulin, growth hormone, cortisol) testing, particularly if an underlying metabolic or toxicologic cause of the patient's hypoglycemia is suspected. However, prompt treatment should not be delayed to facilitate this testing.
Ketones Testing
A urine sample should also be obtained in the ED to evaluate for ketones. As ketones should be present in the setting of hypoglycemia, their absence increases the concern for hyperinsulinism or metabolic disorders such as fatty acid oxidation defects.
Oral Treatment
In the conscious and cooperative child, 15g (or 0.2g/kg for infants) of rapid-acting carbohydrate should be administered by mouth. This is equivalent to four ounces of juice, a tube of glucose gel, or four glucose tablets. In these patients, intravenous (IV) access should be obtained in the case the serum glucose fails to respond to the intervention.
Intravenous Treatment
In a patient with altered consciousness or any concern for the patient's ability to safely attempt oral intake, IV dextrose should be administered rapidly. The goal is for approximately 0.25-0.5g of dextrose per kilogram of body weight, which equates to 2.5-5 mL/kg of 10% dextrose in water or 1-2 mL/kg of 25% dextrose in water. In the first year of life, 10% dextrose should be utilized to minimize risk of vascular injury from infusion. In teenagers and adults, 50mL of 50% dextrose can be given. Symptoms and blood glucose should be monitored every 15-20 minutes after treatment for several hours. Persistent hypoglycemia may require additional dextrose boluses or a continuous infusion. For refractory hypoglycemia, an infusion of dextrose at a rate of 6-8 mg/kg/min should be initiated. Generally, this can be accomplished with 10% dextrose at approximately 1.5 times the maintenance rate.
Pediatric Dextrose Administration in Hypoglycemia
| Age | Dextrose Concentration | Dose |
| Over eight years old | D50 | 1-2 mL/kg |
| One-eight years old | D25 | 2-4 mL/kg |
| Less than one year old | D10 | 5-10 mL/kg |
Intramuscular Treatment
In patients who are unable to take oral carbohydrates and lack IV access, intramuscular glucagon can be considered to acutely increase the plasma glucose at a dose of 0.5mg (<20 kg patient) or 1mg (>20 kg patient). Glucagon is typically only effective for patients with hyperinsulinemia, whether from excess endogenous insulin, surreptitious insulin administration, or sulfonylurea ingestion. This is considered a temporizing measure and is not a substitute for dextrose administration. Octreotide may also be useful specifically in the setting of sulfonylurea-induced hypoglycemia that is not responsive to other therapies.
- Signs and symptoms of hypoglycemia can be nonspecific and broad, particularly in the infant and toddler age groups.
- Failure to consider hypoglycemia in the work-up of a patient presenting with altered mental status can lead to a misdiagnosis or a delay in diagnosis and treatment.
- Do not delay the administration of glucose in a patient demonstrating signs of hypoglycemia if a bedside glucometer is unavailable.
- If safe to do so, initiate enteral glucose administration while awaiting IV access.
- Feed patients enterally following a response to IV dextrose administration.
- Use glucagon in symptomatic hypoglycemic patients who are unable to take oral glucose and who do not have IV access.
- Patients with recurrent hypoglycemia, persistent neurologic deficits, hypoglycemia from an unknown cause, or those with hypoglycemia resulting from insulin use or sulfonylurea ingestion should be admitted for further monitoring.
- De Leon-Crutchlow DD, Lord K. Approach to Hypoglycemia in Infants and Children. UpToDate. 2024.
- Dorney K, Agus MS. Endocrine Emergencies. Fleisher & Ludwig's Textbook of Pediatric Emergency Medicine, 8th edition. Wolters Kluwer. 2021.