Purpose and Goal: CNEP # 2028

  • Understand the challenges of managing neonatal hypoglycemia.
  • Learn about a new strategy for the treatment of hypoglycemia.

None of the planners, faculty or content specialists has any conflict of interest or will be presenting any off-label product use. This presentation has no commercial support or sponsorship, nor is it co-sponsored.

Requirements for successful completion:

  • Successfully complete the post-test
  • Complete the evaluation form

Date

  • October 2015 – October 2017

Learning Objectives

  • Describe normal glucose homeostasis.
  • Describe the characteristics of neonatal hypoglycemia.
  • Describe the use of glucose gel for the treatment of hypoglycemia.

Introduction

  • Hypoglycemia is commonly seen in the neonate
  • It is a leading cause of admission to the NICU
  • It affects as many as 5-15% of neonates
  • Most newborns experience transient hypoglycemia
  • Prolonged hypoglycemia is not normal
    • The brain is dependent on glucose
    • Untreated hypoglycemia → poor outcomes

Fetal Glucose Homeostasis

  • Glucose is a primary source of fetal energy
  • Fetal glucose needs are met by the placenta
  • A continuous supply of glucose is provided
  • Glucose is stored as glycogen
    • Glycogen is initially stored in the placenta
    • By 24 weeks, glycogen is stored in the liver
    • By term, glycogen is stored in cardiac and skeletal muscle

Neonatal Glucose Homeostasis

  • Glucose is a primary source of neonatal energy
  • Neonatal glucose needs are met by intermittent feeds
  • Additionally, fetal glycogen stores are available
    • By term, glycogen liver stores are twice those of adults
    • By term, glycogen cardiac stores are 10 times those of adults
    • Increased glycogen stores balance removal of the placenta
    • Glycogen stores are depleted within 18-24 hours
  • Breakdown of stored glycogen is hormone dependent
    • Insulin
    • Glucagon
    • Catecholamines
    • Corticosteroids
  • There is a normal surge of hormonal activity at birth
    • Transient increase of serum glucose levels
    • Followed by ↓ in glucose levels within 3-4 hours

Hypoglycemia

  • No uniform standards define neonatal hypoglycemia
  • It is difficult to define hypoglycemia by a single number
    • American Academy of Pediatrics definition
    • Glucose levels < 45 mg/dL
  • National Consensus Guidelines
    • All symptomatic neonates
      • Glucose levels < 45 mg/dL
    • All asymptomatic neonates
      • Glucose levels < 40 mg/dL
    • After 24 hours of age
      • Glucose levels < 50 mg/dL

Causes of Hypoglycemia

  • Results from ↓ glucose production and ↑ glucose utilization
    • Diminished glucose supply
      • Inadequate glycogen stores
        • Premature infants
        • SGA infants
    • Impaired glucose production
      • Hyperinsulinism
      • Endocrine Disorders
      • Inborn Errors of Metabolism
    • Increased glucose utilization
      • Sepsis
      • Cold Stress
      • Perinatal Stress/Hypoxia
      • Hyperinsulinism

Pathophysiology of Hypoglycemia

  • Glucose is the primary energy source for the brain
    • It is critical for brain metabolism
    • It is just as vital as oxygen
  • Neonates have a high rate of glucose utilization
    • The neonatal brain is disproportionally large
    • The brain uses up to 95% of available glucose
  • Preterm infants are at higher risk of hypoglycemia
    • Proportionally larger brain size
    • Markedly decreased glycogen stores

Infants of Diabetic Mothers

  • More than 100,000 infants born each year
  • More than 50% will develop hypoglycemia
  • Hypoglycemia is related to hyperinsulinism
    • Fetal exposure to glucose → pancreatic overstimulation
    • Fetal pancreatic overstimulation → hyperinsulinism
    • Fetal hyperinsulinism → decreased utilization of glycogen

Clinical Manifestations

  • Hypoglycemia may be detected by routine monitoring
  • Neonates are frequently asymptomatic
  • Signs can be subtle and non-specific
    • Jitteriness
    • Tremors
    • Irritability
    • Hypotonia
    • Apnea
    • Bradycardia
    • Cyanosis
    • Tachypnea
    • Poor suck
    • Poor feeding
    • Weak cry
    • High-pitched cry
    • Hypothermia
    • Seizures

Identifying Infants at Risk

  • Recognition of infants at risk is critical
  • Infants at risk should be closely monitored
  • There are 4 main groups of at risk infants:
    • Preterm, Post-Term and SGA infants
      • Preterm infants have ↓ glycogen stores
      • SGA infants have ↓ glycogen stores
      • Post-term infants have ↓ glucose transfer
    • Infants of Diabetic Mothers
      • Hyperinsulinism
    • Extremely Low Birthweight Infants
      • Glucose intolerant
      • Insulin resistant
    • Infants Exposed to Maternal Medications
      • Terbutaline
      • Metformin
      • Valproate

Evaluation and Treatment

  • At risk infants should be screened within 1 hour of birth
    • Pre-feed glucose screens are recommended
    • Serum glucose confirmation is recommended
      • Glucose screens are 15% lower than serum levels
      • RBC metabolism continues in serum samples
      • Glucose levels may be artificially decreased
      • Transporting specimens on ice reduces metabolism
    • Follow up screens should be every 1 hour until stabilized
    • Once stabilized, every 4-6 hour screening is adequate
  • Treatment goals are prevention and prompt resolution
  • Adequate oral feeds are essential
  • Continuous glucose infusions may be necessary
  • The use of glucose gel may be beneficial

Treatment with Glucose Gel

  • Hypoglycemia often requires NICU admission
    • Separates the baby from the mother
    • Delays breastfeeding and bonding
  • Even one bottle of formula
    • Negatively affects the infant gut
    • Changes gut flora for up to 4 weeks
  • 40% glucose gel offers an alternative
    • Inexpensive
    • Readily available
    • Noninvasive
    • Easy to administer
  • Oral glucose gel is the first line treatment
    • Older infants
    • Diabetic adults
  • Glucose is the one of the sugars formed
    • When breastmilk is metabolized
    • Does not negatively affect the gut
  • Studies show that glucose gel
    • Is more effective than feeding
    • Decreases the use of formula
    • Supports the use of colostrum
    • Supports exclusive breastfeeding
  • Rebound hypoglycemia has not been found
    • Glucose gel is well tolerated
    • There are no adverse effects
  • 40% gel provides 400 mg/kg glucose
    • It consists of 40% glucose
    • Plus water and glycerin
  • It can be administered in the infants’ cheeks
    • Buccal mucosa is highly vascularized
    • Absorption rate is equal to IV dextrose
  • Dosing is weight based
    • 2.0 kg → 1.00 ml
    • 2.5 kg → 1.25 ml
    • 3.0 kg → 1.50 ml
    • 3.5 kg → 1.75 ml
    • 4.0 kg → 2.00 ml
    • 4.5 kg → 2.25 ml
    • 5.0 kg → 2.50 ml
  • The dose can be easily divided
    • Deliver ¼ or ½ to each cheek
    • Gently massage cheek
    • Repeat as needed
  • When exclusively breastfeeding
    • Gel can be given after a feed
  • When supplementing by bottle
    • Gel can be given before a feed

Long-Term Outcomes

  • Studies have linked hypoglycemia to brain injury
  • Long-term outcomes
    • Smaller head size
    • Developmental delay
    • Poor neurodevelopmental outcomes

Summary

  • Hypoglycemia is a common neonatal disorder
  • Infants may present without symptoms
  • At risk infants should be monitored closely
  • Prevention, early detection and intervention is critical
  • The use of glucose gel may prevent NICU admissions

References

  1. Noerr, B. 2001. State of the Science: Neonatal Hypoglycemia. Advances in Neonatal Care, 1 (1), p. 4-21.
  2. Chan, S.W. 2013. Neonatal Hypoglycemia. Up-To-Date.
  3. Rozanxe, P.J. 2016. Management and Outcome of Neonatal Hypoglycemia. Up-To-Date.
  4. Bennett, C., Fagan, E., Chaharbakhshi, E., Zamfirova, I, and Flicker, J. 2016. Nursing for Women’s Health, 20 (1), p. 63-74.
  5. Harris, D.L., Weston, P.J., Signal, M., Chase, G. and Harding, J.E. 2013. Dextrose Gel for Neonatal Hyoglycemia (the Sugar Babies Study): A Randomized, Double-Blind, Placebo-Controlled Study. The Lancet, 382 (9910), p. 2077-2083.
  6. Evaluation

    *Required fields