Neonatal encephalopathy and HIE — structured oral station (12 minutes)

Opening prompt — "Talk me through your obstetric contribution."

Model response — say it in this order: ^[2]

• "This is a baby with neonatal encephalopathy after an acute intrapartum event. The trace converted from Category I to Category III at 8 cm, the cord arterial gas is pH 6.91 with a base deficit of minus 17, and the infant has moderate-to-severe encephalopathy. He will meet the cooling criteria provided he is under 6 hours old."
• "My obstetric contribution was: senior neonatal team called before the birth, paired cord gases from a double-clamped segment, the placenta sent to histopathology, and a contemporaneous timed note of the trace, the sentinel event, the decision-to-delivery interval and the resuscitation."
• "I would now ensure passive cooling is started while awaiting retrieval — radiant warmer off, baby naked but for a nappy, no wraps, continuous temperature monitoring, target rectal temperature 33 to 34 deg C achieved by 2 hours."^[2]

Probe 1 — "Walk me through the three cooling gates."

• "Gate 1 is an acute perinatal event: Apgar 5 or less at 10 minutes, OR a blood gas within 60 minutes showing pH under 7.0 or base deficit minus 12 mmol/L or worse, OR ongoing resuscitation for 10 minutes or more. This baby meets all three."
• "Gate 2 is moderate or severe encephalopathy: seizures, OR any two of the six modified Sarnat domains altered — consciousness, spontaneous activity, posture, tone, primitive reflexes, autonomic function. This baby has seizures and four domains altered."
• "Gate 3 is the baby: 35 weeks or more, 1800 g or more, less than 6 hours old. He is 39+4 weeks and at 90 minutes — clearly meets."
• "All three gates met; the baby cools."^[2][5]

Probe 2 — "What if the cord pH had been normal?"

• "A normal cord gas does not exclude HIE — about a fifth of babies with proven HIE have normal cord gases — but it pivots the differential. I would look hard for an alternative cause: sepsis, an inborn error of metabolism, perinatal arterial stroke, congenital infection, kernicterus, hypoglycaemia, a structural brain malformation."
• "I would send ammonia, lactate, urine organic acids, plasma amino acids and acylcarnitines early. The diagnosis is made from the totality — gases, trace, sentinel event, MRI, other organs — not from any single test."^[2]

Probe 3 — "How do you document this in a way that protects you?"

This is a scored medico-legal domain. Demonstrate it out loud: ^[2]

• "I avoid the words 'birth asphyxia' and 'fetal distress' — they imply a mechanism I have not demonstrated. I write what I observed, when I observed it, and what I did."
• "I document the four ACOG/AAP 2014 essential criteria: Apgar under 5 at 5 AND 10 minutes; cord arterial pH under 7.0 or base deficit 12 mmol/L or more; MRI or MRS evidence of an acute brain injury pattern; and multisystem organ failure. The diagnosis of an acute intrapartum HIE is supported by the totality of the evidence, not by the Apgar alone."
• "The timed trace, the sentinel event to the minute, the decision-to-delivery interval, the resuscitation duration, the paired cord gases and the placental histopathology — these are what survives to the courtroom."^[2]

Probe 4 — "The mother asks: will my son have cerebral palsy?"

Scored communication domain. ^[2][4]

• "I would move to her eye level, use the baby's name, and say: 'Your son had a difficult time around the birth and the team is concerned his brain may have been affected. He is being cooled — this is a treatment we know helps. It is too early to say what this will mean for his development; we will know more over the coming days and after his MRI at around day 10.'"
• "I would not give a fixed prognosis at 4 hours. I would commit to ongoing communication and to a debrief after the cooling course."^[2][4]

Probe 5 — "What does the evidence show?"

• "Cooling reduces death or major neurodevelopmental disability at 18 months — confirmed in the Cochrane pooled analysis. NICHD 2005 showed a 62% to 44% reduction in death or moderate/severe disability (RR 0.72). TOBY 2009 had a non-significant primary outcome but positive secondary outcomes — survival without neurologic abnormality RR 1.57 — and the TOBY childhood follow-up at 6 to 7 years confirmed durable benefit: 52% vs 39% survived with IQ 85 or higher, cerebral palsy fell from 36% to 21%."
• "The depth-and-duration trial showed 72 hours at 33.5 deg C is a ceiling — longer or colder did not help."
• "HELIX showed cooling is not safe in low-resource settings without intensive care — death alone increased in the cooled group. And the Faix trial showed cooling does not help below 35 weeks."^[3][4][5][6]