Management of Congenital Diaphragmatic Hernia (CDH) CDH has an incidence of 1 in 2500-5000 live births. Nearly 85% are left sided. Most defects (70%) are sporadic. The mortality rates have improved, but still range from 20-60% worldwide, despite maximal therapy, and can be higher if there is an associated cardiovascular defect (40-50% of cases). The main pathophysiological anomalies are pulmonary hypoplasia and pulmonary hypertension. There are many antenatal markers used for determining the prognosis however they are not an accurate reflection of the outcome. Fetal lung:head ratio <1, is used in some centres to indicate a poor prognosis although this is not reproducible in every centre. The presence of an intrathoracic liver indicates a poor prognosis in most centres. FETO (Fetoscopic Tracheal Occlusion) is only used in limited centres. The literature shows that postnatal factors are better indicators for prognosis. Worse prognosis is found with patch repair compared to primary repair, co-existing anomalies (especially cardiac anomalies) and duration of ECMO. The focus of management is on initial stabilisation and ‘gentle’ ventilation before surgery is performed. Management of a baby with known CDH in Labour Ward: 1. 2. 3. 4. 5. 6. Consultant led team with a Registrar and a senior nurse in attendance IM paralysis with Atracurium 0.2 mg/kg as soon as possible after birth If still requires further paralysis and IV access obtained, use IV Pancuronium 100mcg/kg Immediate intubation with largest possible ET tube Bag/ Neopuff mask ventilation is CONTRAINDICATED Large bore NG/OG tube (minimum 10F) or Replogle tube to decompress the stomach – consider continuous suction 7. Maintain temperature during resuscitation and transfer NICU Management and Initial Stabilisation: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Urgent Vascular access - send routine blood samples as per unit protocol Insert Umbilical arterial and venous lines (double lumen preferably) Use conventional ventilation initially but have a low threshold for changing to oscillation Chest x-ray to confirm diagnosis and to aid decisions regarding ventilation Maintain homeostasis: particularly glucose and calcium homeostasis. Maintain Hb above 130g/L, but avoid polycythaemia. Consider Surfactant after discussion with the Consultant Monitor transcutaneous pO2 and pCO2 Bladder catheterisation Sedation with IV Morphine/Fentanyl Continuing paralysis with Vecuronium infusions; long-term paralysis maybe counterproductive. Cranial USS to exclude IVH (Nitric oxide may be contraindicated if > Grade II IVH) Arrange for cardiac ECHO to assess pulmonary pressures and to exclude any cardiac anomalies; serial ECHOs will be needed to assess changes in pulmonary arterial pressures over the next few days. Ventilation: 1. Aim to keep Preductal saturations >90% using the lowest PIPs (try to avoid exceeding PIPs >25 cmH2O). PEEP 5-6 cm H2O. 2. Consider HFO if failing on conventional ventilation 3. Aim for normal pCO2 values at 6 kPa and pH above 7.30 4. Measure Oxygen Index (OI) with every gas: Oxygen Index = (MAP mmHg x FiO2 %) / PaO2 mmHg 5. Add Nitric oxide (iNO) 20ppm – add if: a) Post ductal pO2 < 80mmHg (11kPa) and /or rd b) Significant R→L shunting + RV pressure >2/3 systemic on ECHO - When the FiO2 is < 50%, start weaning NO - Be aware that Nitric oxide may not work for PPHN in CDH. - If no response and the OI >20 (for definition see PPHN guideline) on 2 successive gases suggests poor response to iNO therefore consider stopping - Failure of iNO may warrant discussion with the cardiologists for a trial of other therapies - e.g. Sildenafil, Magnesium Sulphate, Adenosine, or Bosentan ECMO: If there is no improvement in ventilation contact ECMO centre for advice. Consider ECMO early ideally before the following occur: Inability to maintain preductal Sats >85% or postductal Sats >70% Dr Ruth Hanks, Dr Alok Sharma and Dr Sybil Barr July 2014, to be re-evaluated July 2017. Acidosis with pH <7.15 despite optimal ventilation If PIP >28cm H2O or mean airway pressure >17 cmH2O needed to achieve Sats >85% Elevated Lactate >5mmol/L Systemic hypotension resistant to fluid or inotropic resuscitation, and urine output <0.5mL/kg/hr Persistently elevated OI >30 Circulation: 1. Mean BP (measured invasively) maintained above the pulmonary arterial pressure as estimated on ECHO. 2. Ensure adequate preload with generous volume administration particularly if IVC collapsed on ECHO (see Hypotension guidelines) 3. Dopamine is the first choice and adrenaline is the 2nd choice inotrope. 4. Monitor arterial pH, serum lactate and urine output • Maintain pH>7.30, arterial lactate < 1mmol/L, and urine output > 2ml/kg/hour 5. Milrinone may be used in refractory pulmonary hypertension and poor cardiac output - liaise with cardiologists. Surgery: To be considered when cardiovascular status is stable for at least 24 hours; off all inotropes and the pulmonary arterial pressures is improving and FiO2 < 0.5. Most cases have a primary closure (60-70%) and the remainder usually require a patch repair. Patch repair is usually used with larger defects and has a greater correlation with GORD. Long-term outcome: Overall operated survival to discharge is 70-90% (decreasing to 50% when ECMO required - often associated with a larger defect and more severe primary disease). Survival at 1 year is ~37%. There have been various associated morbidities reported: Chronic lung disease in severe CHD (50%), persistent wheezing (60%), GORD (50%), hearing loss and other neurodevelopmental problems (20%). References 1. Bösenberg, Adrian T et al; Management of congenital diaphragmatic hernia; Current opinion in Anaesthesiology; Volume 21(3), June 2008, p 323–331 2. Anthony S de Buys Roessingh et al; Congenital Diaphragmatic hernia; current status and review of literature; EurJ Pediatr(2009)168:393-406 3. Hadi Mohseni-Bod MD et al; Pulmonary hypertension in congenital diaphragmatic hernia Seminars in Pediatric Surgery; Volume 16, Issue 2, May 2007, Pages 126-133 4. J. Wells Logan MD et al; Mechanical ventilation strategies in the management of congenital diaphragmatic hernia; Seminars in Pediatric Surgery;Volume 16, Issue 2, May 2007, Pages 115-125 5. Haroon J. et al; An Evidence-Based Review of the Current Treatment of Congenital Diaphragmatic Hernia; Clinical Pediatrics; Volume 52; 2013; p 115. 6. Hedrick MD et al. Management of prenatally diagnosed congenital diaphragmatic hernia. Seminars in Pediatrics; Vol 22; Issue 1; 2013; p 37-43 7. Cundy TP et al; Fetoscopic endoluminal occlusion (FETO) for congenital diaphragmatic hernia in Australia and New Zealand: Are we willing, able, both or neither?; J Paediatr Child Health; Volume 50, Issue 3, March 2014; p 226-33 Drug Dopamine Dobutamine Adrenaline Milrinone Dose 2-5mcg/kg/min Mode of action Dopaminergic effects 5-10 mcg/kg/min β adrenergic effects >10mcg/kg/min 2-20mcg/kg/min α effects Direct stimulation of myocardial α adrenergic receptors Peripheral β adrenergic receptors β effects at lower dose 0.5- 1mcg/kg/min 50-75 mcg/kg over 15-60 min, then 22.5 – 60 mcg/kg/hour α effects at high dose Selective inhibitor of Phosphodiesterase lll Comments Increased visceral blood flow ↑ myocardial contractility ↑Preload and systemic vascular resistance (SVR); ↓renal blood flow ↑ Stroke volume, ↑HR ↓SVR Improves LV function Vasoconstriction; ↑SVR Improves LV function without increasing SVR; ↓PVR and Pulm artery pressures Useful for refractory Pulm. HT Dr Ruth Hanks, Dr Alok Sharma and Dr Sybil Barr July 2014, to be re-evaluated July 2017. Dr Ruth Hanks, Dr Alok Sharma and Dr Sybil Barr July 2014, to be re-evaluated July 2017.