CDH is a congenital defect in the diaphragm (usually detected antenatally) resulting in herniation of abdominal contents into the thoracic cavity; associated with a high risk of mortality and morbidity. A combination of pulmonary hypoplasia and abnormal morphology of the pulmonary vasculature leads to severe respiratory insufficiency and increased risk of developing persistent pulmonary hypertension (PPHN)

Antenatal diagnosis

• Delivery to be planned at regional neonatal intensive care unit (NICU)
• Fetal medicine team and paediatric surgeon to provide antenatal counseling 
• Neonatal team to meet parents before delivery
• Neonatal consultant, middle grade, junior tier and NICU nurse to attend delivery

Postnatal diagnosis

• In some babies the lesion develops later in gestation; these babies tend to have a better prognosis
• Postnatal presentation can be with clinical features ranging from inability to resuscitate baby at birth to incidental finding on chest X-ray

• Pre and postductal SpO₂
• Chest and abdominal X-ray
• Arterial blood gas
• Echocardiogram 

Key principles

• Intubate all antenatally diagnosed babies promptly (intubation to be carried out by most experienced and reliable operator present)
• Optimise ETT position and size, aiming for little or no leak, with largest size tube feasible
  
  • confirm tube position by end tidal CO₂ monitoring
• Do not give mask ventilation – will introduce air into the GI tract and compromise ventilation
• Maintain low peak pressure <25 cm H₂O and positive end expiratory pressures of 5 cm H₂O to avoid lung damage
• Avoid high airway pressures
• Establish adequate perfusion and oxygenation
  
  • aim for preductal SpO₂ 80–95% after first 10 min
  • avoid hyperoxia, reduce FiO₂ when preductal saturation >95%
• Insert large gauge 8–10 Fr NGT
  
  • aspirate at least every 5 min to decompress stomach until baby established on ventilation, then place on free drainage 
• Check temperature before transfer to NNU, maintain normothermia
• Examine baby for other associated abnormalities e.g.:
  
  • cardiac (present in 20%)
  • trisomy 18/21
  • urogenital
  • musculoskeletal

• Weigh baby
• Start on conventional ventilation with low tidal volume strategy of 3–4 mL/kg
• Sedation: morphine 20 micrograms/kg/hr 
• Umbilical venous and arterial catheters 
  
  • to be sited by experienced operator (initial management is time critical)
  • if not possible to site umbilical arterial catheter (UAC), insert peripheral arterial line 
• Monitor pre and postductal SpO₂ 
  
  • first 2 hr only: if pH >7.2, PaCO₂ <8.6 kPa and saturations improving, aim for preductal saturations of >70%
  • after first 2 hr: if lactate and pH acceptable (pH >7.2, lactate <5 mmol/L) on arterial blood gas, aim for preductal SpO2 80–95% (UAC measures postductal PaO₂) and postductal SpO₂ >70%
  • an abnormal lactate is an indicator of poor perfusion and must be corrected before the interpretation of acceptable levels of SpO₂
• Maintain arterial blood pressure at normal level for gestational age 
• Surfactant NOT routinely recommended. Only to be administered after discussion with regional centre as risk of over-distension and pneumothorax
• Cardiac echocardiogram (ideally within 6 hr of birth) to:
  
  • exclude associated congenital cardiac disease 
  • assess right ventricular function 
  • look for evidence of persistent pulmonary hypertension [see Persistent pulmonary hypertension of the newborn (PPHN) guideline] 
  • identify patent ductus arteriosus and assess shunting (see Patent ductus arteriosus guideline)

Ventilation

Gentle conventional (see Ventilation: conventional guideline)

• Avoid peak pressures >25 cm H₂O, maintain PEEP 3–5 cm H₂O
  
  • if greater peak pressures required to maintain preductal SpO₂ >80% and postductal SpO₂ >70%, discuss HFOV with consultant 
    
    • if HFOV not available discuss with specialist centre e.g. KIDS NTS/BWCH to expedite retrieval

HFOV [see Ventilation: high frequency oscillatory (HFOV)guideline]

• Initial setting:
  
  • MAP: 12 cm H₂O (do not increase >16 cm H₂O)
  • rate/frequency: 10 Hz, delta P 25
• Chest X-ray 1 hr after commencing HFOV
  
  • if >8 rib spaces visible, lungs are hyper-inflated – reduce MAP

Target O₂ saturations

• Aim for preductal SpO₂ of 80–95% 
  
  • if MAP >12 cm H₂O and FiO₂ >0.6 to maintain preductal SpO₂ >80%, commence inhaled nitric oxide (iNO) at 20 ppm (see Nitric oxide guideline)

Permissive hypercapnia

• If pH >7.2, lactate <5 and urine output >1 mL/kg/hr: target PaCO₂ 6.9–9.3 kPa 

Systemic blood pressure support

• Invasive blood pressure monitoring required
• If preductal SpO₂ 80–95%, aim for mean arterial blood pressure corresponding to gestation
• Maintenance fluid volume: 60 mL/kg/day
• Treat hypotension or poor tissue perfusion (rising lactate, urine output <1 mL/kg/hr) with fluid boluses sodium chloride 0.9% 10 mL/kg (maximum 30 mL/kg)
• If heart rate normal, urine output >1 mL/kg/hr, lactate <3 – do not give inotropes 
• If persistent hypotension or hypoperfusion and difficulty maintaining preductal saturation 80–95%, give inotropes

Term baby

• Start adrenaline 100–1000 nanogram/kg/min as first line (starting dose usually 300 nanogram/kg/min)
• If right ventricular failure on echocardiogram discuss adrenaline with specialist centre e.g. KIDS NTS 
• If right ventricular failure add milrinone 35–45 microgram/kg/hr (starting dose 35 micogram/kg/hr; DO NOT give loading dose) and noradrenaline 20–100 nanogram/kg/min (starting dose 20 nanogram/kg/min) 

Preterm baby

• Start dopamine 10 microgram/kg/min and increase to 20 microgram/kg/min
  
  • if excessive tachycardia (heart rate >200 bpm) secondary to dopamine, discuss with specialist centre e.g. KIDS NTS and add noradrenaline
• Monitor lactate – rise in lactic acidosis suggests excessive vasoconstriction by inotropes

Metabolic acidosis

• Accept pH >7.2
• Review vasoconstrictor effects versus benefits of inotropes
• Correct metabolic acidosis with sodium bicarbonate 4.2%; give full correction over 6 hr titrating against pH/base excess every 1–2 hr

• Anticipate PPHN in babies with CDH 
• Monitor pre and postductal SpO2
• Calculate oxygenation index (OI) (UAC is a measure of postductal saturation)
  • if OI >20 and/or pre:postductal saturation difference >10% discuss with tertiary centre e.g. KIDS NTS to expedite retrieval 
• Initiate trial of iNO, 20 ppm for 1 hr 
• Magnesium sulfate (MgSO₄) is an effective pulmonary vasodilator, commence an infusion of MgSO₄ to achieve serum (Mg) above the normal range (>1 mmol/L)
  • can give rise to profound systemic hypotension, use only in conjunction with active management of systemic blood pressure support
• Maintain arterial PaO₂ 8–10 kPa
• See Persistent pulmonary hypertension of the newborn (PPHN) guideline

• Fluid: restrict to 60 mL/kg/day
• Keep large bore NGT on free drainage and regular aspiration, and nil-by-mouth. Buccal colostrum can be given if available
• Commence parenteral nutrition
• Send blood culture and commence first line antibiotics
• Send clotting screen and correct any abnormalities
• Correct hypocalcaemia 
• If antenatal diagnosis of a duct dependent congenital cardiac lesion, or any uncertainty about the presence of cardiac anomaly, commence dinoprostone (prostaglandin E₂) 5 nanogram/kg/min
• Maintain magnesium >1 mmol/L
• Maintain normothermia
• Monitor for pneumothorax. See Chest drain insertion – Seldinger technique and Chest drain insertion – Traditional guidelines 
• Crossmatch 1 unit of blood
• Cranial ultrasound scan
• Send blood for chromosomes with parental consent (if not done antenatally)
• Sedation: morphine 10–20 microgram/kg/hr, but avoid deep sedation
• Avoid neuromuscular blocking agents – use is associated with hypoxaemia
• Minimal handling, developmental care with swaddling/cocooning
• Keep area around baby quiet and lights dimmed

• Neonatal consultant to inform planned paediatric specialist centre e.g. Birmingham Children’s Hospital/Birmingham Women’s Hospital once baby stabilised. This will require conference call with referring consultant, on-call surgeon at specialist centre, neonatologist, PICU intensivist and transport consultant e.g. KIDS NTS, to discuss urgency of transfer and ongoing management
• Undertake transport of babies for surgery only when:
  
  • mean arterial blood pressure normal for gestation
  • lactate <3 mmol/L and urine output >1 mL/kg/hr
  • ventilation reduced to low pressure settings
  • FiO₂ on conventional ventilation 0.5, with preductal saturations 85–95%
  • baby fit for surgery and stable for ≥24 hr (may take ≥3–10 days) 

• See Persistent pulmonary hypertension of the newborn (PPHN) guideline
• If ECMO considered refer to specialist centre (e.g. via KIDS NTS team)

• https://bwc.nhs.uk/paediatric-surgery-treatments
• https://kids.bwc.nhs.uk/
• https://www.e-lfh.org.uk/programmes/paediatric-surgery/