What is the first step in managing seizures in a newborn, focusing on glucose or calcium?

Management of Neonatal Seizures: Glucose First

Check and correct glucose immediately as the first priority in any newborn presenting with seizures, followed by assessment and correction of calcium if hypoglycemia is excluded. 1, 2

Immediate Actions During Active Seizure

• Position the newborn on their side in the recovery position to reduce aspiration risk during active seizure activity 1
• Clear the area around the infant to prevent injury 1
• Do not place anything in the mouth or attempt oral glucose/medications during the seizure, as this causes more harm 1
• Do not restrain the seizing infant 1
• Maintain airway patency and provide high-flow oxygen 1
• Activate emergency services immediately for any newborn with seizure, particularly infants under 6 months of age 3, 1

Diagnostic Approach: Glucose Takes Priority

Step 1: Check Blood Glucose Immediately

• Hypoglycemia is the most common treatable metabolic cause of neonatal seizures and represents a preventable cause of mental retardation and permanent brain damage 2, 4
• Use blood gas analyzers with glucose modules for most accurate measurements, as handheld glucose meters have significant accuracy concerns in newborns due to interference from high hemoglobin and bilirubin levels 5, 1
• Critical hypoglycemia thresholds requiring immediate intervention:
  • Single measurement <1 mmol/L (18 mg/dL) 5
  • Glucose <2 mmol/L (36 mg/dL) that remains low at next measurement 5
  • Any glucose <2.5 mmol/L (45 mg/dL) in a newborn with abnormal clinical signs like seizures 5

Step 2: Administer Intravenous Glucose

• Intravenous glucose is the primary treatment for newborns with active seizures or altered consciousness, since oral administration is contraindicated during seizures 1
• Maintain blood glucose >50 mg/dL (2.8 mmol/L) until diagnosis is established 4
• Provide D10%-containing isotonic IV solution at maintenance rate to deliver age-appropriate glucose (8 mg/kg/min in newborns) 3

Step 3: Assess Calcium After Glucose Correction

• Hypocalcemia is a frequent, reversible contributor to cardiac dysfunction and seizures in neonates 3, 6
• Check ionized calcium concentration as part of the diagnostic workup 3, 4
• Calcium replacement should be directed to normalize ionized calcium concentration if hypocalcemia is confirmed 3
• Hypocalcemic seizures can occur even in term infants with no apparent risk factors, sometimes related to maternal calcium ingestion causing transient neonatal hypoparathyroidism 6

Post-Seizure Monitoring

• Monitor hourly capillary glucose, heart rate, respiratory rate, blood pressure, and neurologic status after seizure cessation 1
• Repeat laboratory tests (electrolytes, blood glucose, blood gases) every 2-4 hours 1
• Provide oral carbohydrates to prevent recurrence once the infant is awake and able to swallow safely 1
• If the newborn does not return to baseline within 5-10 minutes after seizure stops, this requires continued emergency medical intervention 3, 1

Critical Pitfalls to Avoid

• Never attempt oral glucose during active seizures - this is contraindicated and dangerous 1
• Do not delay glucose administration while waiting for calcium results, as severely low, prolonged, recurrent hypoglycemia with seizures is clearly associated with permanent brain damage 7, 8
• Avoid over-treating calcium as toxicity may occur with elevated concentrations 3
• Persistent hypoglycemia requires urgent investigation for hyperinsulinemia, hypopituitarism, or hereditary hepatic enzyme deficiencies 2, 4
• Obtain diagnostic tests at presentation including blood for insulin, cortisol, growth hormone, and urine for ketone bodies when hypoglycemia is confirmed 4

Why Glucose Takes Priority

The rationale for checking glucose first is straightforward: hypoglycemia is the most common metabolic disorder in neonates, it is immediately life-threatening to brain tissue, and it requires urgent correction to prevent irreversible neurologic injury 2, 8. Seizures with extremely and persistently low plasma glucose concentrations (0 to <1.0 mmol/L for more than 1-2 hours) in the absence of other CNS pathology are diagnostic of hypoglycemic brain injury 7. While hypocalcemia is also an important treatable cause of neonatal seizures 6, glucose assessment and correction must come first given its higher prevalence and the critical time-sensitivity of treatment 2, 4.