Sarnat Staging – Hypoxic-Ischemic Encephalopathy (HIE)
Structured aid to classify neonatal HIE as mild (Stage I), moderate (Stage II), or severe (Stage III) based on Sarnat criteria.
For use by neonatal health professionals only. This tool approximates Sarnat staging by counting how many clinical domains fall into Stage I, II, or III patterns. It does not replace full neurological examination, EEG/aEEG, local protocols, or expert judgement – especially when evaluating eligibility for therapeutic hypothermia or prognostication.
Enter current clinical findings
Domain counts – Stage I: –, Stage II: –, Stage III: –
Suggested Sarnat stage: Not yet calculated
Severity of HIE: –
Select clinical findings in each domain and click “Determine Sarnat stage” to see a suggested Sarnat category (I–III). Always confirm by full neurological assessment and serial exams.
This tool approximates Sarnat staging by majority pattern across domains. In real practice, staging should incorporate evolution over time (first 24–72 hours), antenatal history, cord/early blood gases, imaging, and EEG/aEEG. Use your local guidelines when considering therapeutic hypothermia and prognostication.
Sarnat staging is a clinical system used to classify the severity of hypoxic-ischemic encephalopathy (HIE) in (usually term) newborns after perinatal asphyxia.
It was originally described by Sarnat & Sarnat (1976) and remains the standard framework used in NICUs worldwide to:
- Grade encephalopathy as mild (Stage I), moderate (Stage II), or severe (Stage III)
- Guide decisions about therapeutic hypothermia, monitoring, prognosis discussions, and follow-up
Structure of Sarnat Staging
Sarnat assesses multiple domains over time (often serially in the first 24–72 hours):
- Level of consciousness – hyperalert, lethargic, stuporous/comatose
- Neuromuscular control – muscle tone, posture, activity
- Primitive reflexes – suck, Moro, grasp
- Autonomic function – pupils, heart rate, respiration, GI function
- Seizures – absent, clinical seizures
- EEG (where available) – normal, abnormal, burst suppression/isoelectric
Typical pattern:
- Stage I (Mild HIE)
- Hyperalert, normal or mildly increased tone, exaggerated Moro, strong suck
- No seizures
- Usually resolves within 24 hours
- Stage II (Moderate HIE)
- Lethargic, hypotonia or mild hypertonia, weak/poor suck, incomplete Moro
- May have clinical seizures
- Autonomic instability (miosis/mydriasis, brady/tachycardia, apnea)
- Often the main target group for therapeutic hypothermia (within eligibility criteria & timeframe)
- Stage III (Severe HIE)
- Stupor or coma, flaccid tone, absent suck and Moro
- Often prolonged seizures early, then may be absent with severely depressed EEG
- Abnormal respiration, autonomic failure, multiorgan involvement
Sarnat staging is clinical, somewhat subjective, and done serially—babies may evolve from I → II or III over the first day. It’s a framework, not a numerical score, but many centres use structured checklists to standardise staging.
