Paediatric anaesthesia13 / 17
Congenital diaphragmatic herniaTerm newborn boy, day 4, 3.2 kg, with a left congenital diaphragmatic hernia
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Know this first
- Lung hypoplasia raises PVR and drives right-to-left ductal shunting.
- Stabilise first: preductal SpO2 at least 90%, acidosis corrected, lowest ventilator settings.
- No bag-mask ventilation; it distends the gut in his chest.
- Airway pressure stays below 25–30 cmH2O; the hypoplastic lung is not forced open.
- Hypoxia, high CO2, acidosis and cold all raise his PVR.
The patient
Term newborn boy, day 4, 3.2 kg, with a left congenital diaphragmatic hernia, intubated at birth.
Echo: pulmonary hypertension with right-to-left ductal flow. On a dopamine infusion and sedation; peak pressure 22 cmH2O, FiO2 0.5.
Now stabilised for delayed repair.
Vitals: HR 150, BP 58/34, preductal SpO2 93%, postductal 84%, PaCO2 58 mmHg, pH 7.30.
The examiner asks
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Consider
What are your considerations?
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- A 4-day-old with a left CDH and pulmonary hypertension, ventilated, for delayed repair. Patient
- As a newborn his PVR is reactive; hypoxia, acidosis or cold can reopen fetal shunts.
- Hypoplastic lungs and high PVR: his pre- to postductal gap shows right-to-left shunting. Disease
- Repair waits for stability; it is no longer a surgical emergency. Surgery
Prepare
How do you prepare him?
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- Stable means preductal saturation at least 90%, acidosis corrected, low pressures. Stem trigger
- Pre- and postductal oximeters, and a right radial arterial line. Disease
- Venous access in his arms, not legs; reduction can compress his IVC. Surgery
- Inhaled nitric oxide, oscillator and ECMO team arranged before we start. Crisis
Plan
How do you conduct the anaesthetic?
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- Opioid-based anaesthesia with a relaxant; low-dose volatile only if tolerated; no nitrous oxide. Disease
- Gentle ventilation, accepting moderate hypercapnia.
- Airway pressures kept under 25–30 cmH2O to avoid pneumothorax.
- No attempt to inflate the hypoplastic lung after reduction. Surgery
- Deep, warm and well oxygenated: no hypoxia, acidosis or cold. Disease
- Back to the neonatal unit ventilated. After surgery
Crisis
After reduction, SpO2 drops to 65%, BP 40/22, and right-sided breath sounds vanish. What do you do?
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- Likely a right pneumothorax: gentle hand ventilation on 100% oxygen. (Crisis)
- Tell the surgeon; the right chest is decompressed and drained now.
- DOPE check meanwhile: tube position and patency, equipment.
- Fluid and inotrope to support his pressure.
- HR under 60 despite ventilation: start chest compressions.
Crisis
Later, preductal SpO2 falls to 75%, postductal 55%; BP 45/25. What do you do?
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- Pulmonary hypertensive crisis: 100% oxygen and deeper anaesthesia. (Crisis)
- Correct acidosis and CO2 without pushing up his airway pressures.
- Inhaled nitric oxide to lower his PVR.
- Inotropes to hold his systemic pressure.
- Not responding: ECMO.
Fatal mistakes
- Bag-mask ventilation that fills the bowel in his chest.
- High-pressure ventilation of hypoplastic lungs.
- Emergency repair before stabilisation.
- Missing a contralateral tension pneumothorax.
Checked against: Stoelting 8e · Miller 10e
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