What is the management for hypoxic ischemic encephalopathy?

Management of Hypoxic Ischemic Encephalopathy

Therapeutic hypothermia is the standard of care for term or near-term infants (≥36 weeks gestation) with moderate to severe HIE and must be initiated within 6 hours of birth to reduce death or major neurodevelopmental disability by 22-33%. 1, 2

Immediate Assessment and Eligibility Criteria

Evaluate infants for therapeutic hypothermia using the following criteria:

• Gestational age: ≥36 weeks 2
• Evidence of perinatal asphyxia: Apgar score ≤5 at 10 minutes, need for resuscitation at 10 minutes, or severe acidosis 2
• Encephalopathy severity: Altered level of consciousness, abnormal tone, abnormal reflexes, or seizures indicating moderate-to-severe HIE 2
• Time window: Must initiate cooling within 6 hours of birth 3, 1, 2

Therapeutic Hypothermia Protocol

Core temperature management:

• Target temperature: 33-34°C (whole body or selective head cooling) 3, 2, 4
• Duration: 72 hours of continuous cooling 3, 1, 2
• Rewarming: Slowly at 0.5°C per hour over minimum 4 hours 3, 2, 4
• Location: Only in neonatal intensive care facilities with multidisciplinary care capabilities 3, 1, 2

Expected outcomes with treatment:

• Reduces death or major neurodevelopmental disability by 22-33% 1, 2
• Number needed to treat: 5-7 infants to prevent one case of death or significant disability 1, 2
• Reduces cerebral palsy risk by 48% 1
• Reduces deafness risk by 58% 1
• Greater benefit in moderate HIE (33% reduction) compared to severe HIE (17% reduction) 1

Supportive Care During Hypothermia

Respiratory management:

• Begin with airway management and effective ventilation as primary focus 2
• Start with room air (21% oxygen) for term infants, not 100% oxygen 2
• Titrate oxygen based on pulse oximetry readings 2
• Maintain adequate oxygenation to prevent hypoxemia 4
• Target PaCO₂ of 4.5-5.0 kPa 4

Hemodynamic management:

• Maintain systolic blood pressure >110 mmHg 4
• Position with 20-30° head-up tilt to optimize cerebral perfusion 4
• Use 0.9% saline as crystalloid of choice 4
• Monitor for hypotension (known complication of cooling) 3, 2

Metabolic management:

• Initiate intravenous glucose infusion as soon as practical after resuscitation 3, 2
• Goal is avoiding hypoglycemia, as lower blood glucose correlates with worse brain injury 3

Monitoring for complications:

• Thrombocytopenia 3, 2
• Increased need for inotropic support 2
• Avoid extreme hypothermia through strict temperature monitoring 1

Seizure Management

• Treat epileptic seizures that affect quality of life with anticonvulsants 4
• Administer at sufficiently high dose and for sufficiently long duration 4
• Consider alternative routes (buccal, intramuscular, subcutaneous, rectal) if needed 4
• Perform EEG to differentiate hypoactive delirium from non-convulsive status epilepticus 4

Critical Pitfalls to Avoid

Timing errors:

• Never initiate cooling beyond 6 hours of life as efficacy decreases significantly 2
• Do not delay assessment—the 6-hour window is absolute 1, 2

Facility limitations:

• Do not attempt therapeutic hypothermia without proper monitoring equipment and trained staff 2
• Required resources include: IV therapy, respiratory support, pulse oximetry, antibiotics, anticonvulsants, and pathology testing 1, 2

Temperature management errors:

• Avoid iatrogenic hyperthermia during and after treatment 3
• Do not rewarm too rapidly—minimum 4 hours required 3, 2

Prognostication errors:

• Avoid early prognostication to prevent self-fulfilling prophecy bias 4
• Most crucial evaluation occurs after rewarming 4
• Rule out confounding factors (sedatives, electrolyte disturbances, hypothermia) before prognostication 4

Long-Term Follow-Up

• All treated infants require longitudinal follow-up 3
• Use multidimensional assessment including cerebral imaging, EEG, and neuron-specific enolase 4
• Monitor for developmental disabilities across all domains 5