How to manage convulsions in a newborn, particularly those with a history of birth asphyxia or other perinatal complications?

Management of Neonatal Convulsions

Immediate Acute Seizure Control

For newborns with convulsions, particularly those with birth asphyxia, administer phenobarbital as the first-line anticonvulsant with an intravenous loading dose of 15-20 mg/kg, which achieves therapeutic plasma levels within minutes and controls seizures in most cases. 1, 2, 3

First-Line Treatment: Phenobarbital

• Administer phenobarbital IV loading dose of 15-20 mg/kg to achieve therapeutic plasma concentrations (15-30 mcg/mL) within minutes 2
• This loading dose provides seizure control that remains stable for approximately 48 hours without significant fluctuation 2
• Phenobarbital is FDA-approved for emergency control of acute convulsive episodes in pediatric patients, including neonates 4
• It is specifically recommended as the drug of choice for convulsions in term neonates with perinatal asphyxia 2, 3

Second-Line Treatment if Seizures Persist

• Do not add additional anticonvulsants until phenobarbital plasma levels exceed 40 mcg/mL 2
• If seizures continue despite adequate phenobarbital levels (>40 mcg/mL after 10-15 minutes), consider rectal diazepam 0.5 mg/kg 1
• Alternatively, continuous IV diazepam infusion at 1.0-1.5 mg/hour can be used for refractory seizures, though this requires close respiratory monitoring 5

Critical Diagnostic Evaluation

Mandatory Investigations for Neonates (0-29 days)

• Perform lumbar puncture in all infants <12 months with seizures to exclude meningitis, as meningeal signs may be absent in this age group 6, 1
• Check blood glucose immediately during or after seizure to rule out hypoglycemia 6, 1
• Obtain urinalysis to exclude urinary tract infection, the most common serious bacterial infection in febrile infants 7, 1
• MRI head with diffusion-weighted imaging is the most sensitive modality for detecting hypoxic-ischemic injury when performed at the appropriate time interval 8
• Head ultrasound can serve as initial bedside imaging for unstable neonates to identify intraventricular hemorrhage, hydrocephalus, or white matter changes, though it has low sensitivity for hypoxic-ischemic injury 8

Identify Underlying Etiology

• Hypoxic-ischemic encephalopathy accounts for 46-65% of neonatal seizures and is the most common cause in both term and preterm infants 8
• Intracranial hemorrhage and perinatal ischemic stroke account for 10-12% of cases 8
• Approximately 90% of infants with hypoxic-ischemic encephalopathy develop seizures within the first 2 days after birth 8
• Seizures occurring after day 7 of life are more likely related to infection, genetic disorders, or malformations of cortical development 8

Maintenance Anticonvulsant Therapy

Phenobarbital Dosing After Loading

• Administer maintenance dose of 3-4 mg/kg/day starting 24 hours after loading dose 2
• Do not exceed 5 mg/kg/day to avoid drug accumulation, given the long plasma half-life of 69-165 hours in neonates 2
• Monitor phenobarbital levels if therapy extends beyond 48 hours to prevent toxicity 2
• Duration of therapy depends on clinical condition, but early discontinuation after 1-2 weeks is generally possible 2

Supportive Care in First 48 Hours

Meticulous supportive care during the first 48 hours after asphyxia is essential to prevent ongoing brain injury in the penumbra region. 3

Critical Parameters to Monitor and Correct

• Maintain normothermia: Temperature instability worsens neurologic outcomes 3
• Correct hypoglycemia promptly: Check and maintain blood glucose levels 6, 1, 3
• Maintain adequate blood pressure: Hypotension reduces cerebral perfusion 3
• Ensure appropriate oxygenation: Avoid both hypoxia and hyperoxia 3
• Monitor for multi-organ dysfunction: Asphyxia affects kidneys, lungs, liver, and cardiovascular system 3, 9

Criteria for Hospitalization vs. Outpatient Management

All Neonates with Seizures Require Hospitalization

• Infants <3 months with fever and seizures must be hospitalized due to immature immune systems and high risk of serious bacterial infection 7, 1
• Neonates with seizures lasting >20 minutes or who have not fully recovered within 1 hour require admission 1
• Any neonate with toxic appearance, abnormal CSF findings, or difficulty feeding requires hospitalization 7

Fever Management (If Present)

• Use paracetamol (acetaminophen) as the preferred antipyretic for comfort, not to normalize temperature 7, 6, 1
• Do not use physical cooling methods (tepid sponging, cold bathing, fanning) as they cause discomfort without proven benefit 7, 6
• Ensure adequate hydration to prevent dehydration 7, 6

Common Pitfalls to Avoid

• Do not continue injecting phenobarbital until convulsions stop, as it requires 15+ minutes to reach peak brain concentrations; over-administration causes severe barbiturate-induced depression 4
• Do not routinely perform EEG, serum electrolytes, or chest X-ray unless specific clinical indication exists 6
• Do not use antipyretics to prevent febrile seizures—they are ineffective for this purpose 8
• Do not restrain the seizing infant or place anything in the mouth 8

Parent Education and Follow-up

• Provide parents with specific information on seizure nature, recurrence risk (approximately 30%), and warning signs requiring immediate return 7, 6
• For febrile seizures, parents may be given rectal diazepam for home administration at seizure onset to prevent prolonged recurrent episodes 6
• Reassure parents that simple febrile seizures have excellent prognosis for normal neurological development 6, 1
• Reevaluate within 24 hours if managed as outpatient, though most neonatal seizures require inpatient management 7, 6