☛ Incidence – 1:2500
☛ M:F – 2:1
☛ Lt > Rt -5:1
Present as a true neonatal emergency requiring rapid resuscitation – correction of metabolic acidosis, fluid deficit, correction of hypothermia & baby prepared for emergency sx.
- Failure of closure posterolateral part of diaphragm ( foramen of Bochdalek) or non fusion of anterior ,lateral or central portion of diaphragm retrosternaly ( Foramen of morgagni) by the 7- 8th wk of gestation produce debects in diaphragm.
- Slowly the growing gut or abdominal viscera migrate into the pleural cavity and causes vertilatory and circulatory crisis with pulmonary hypoplasia .
- The time at which thorax gets involved is important as it decides the degree of pulmonary hypoplasia and prognosis .
Migration of Abdominal viscera into Thorax
⤋ ⤋ ⤋
Medistinal shift compression atelectasis Lung hypoplasia
⤋ ⤋ ⤋
↓ed venous return shunt & hypoxia Resparatory Acidosis
⤋ ⤋ ⤋
↓ed cardiac output Inadequate vent. Met & Resp. Acidosis
- The spectrum of clinical presentation varies ,depending upon the period of lung invasion and pulmonary agenesis
- The commonest site is left sided foramen of Bochdalok.
Causes of hypoxia in CDH
- Atelactasis – compression of developed lung
- Pessistent pul. hypoplasia due to ↓ed bronchopulmonary generation & pul vasculature
- Persistent pulmonary HTN
- Return of fetal circulation leading to R -> it shunt through ductus arteriosus or foramen ovale.
- Systemic hypotension following kinking of major blood vessels.
Classification of CDH
- Absent diaphragm – very rare
- Diaphragmatic hermia
I Posterolateral Foramen of Bochdeck -80 %
I V Eventration rare
Assement of severity of pulmonary hypoplasia
- PAO2 –PaO2 difference > 500 mm Hg with 100 % O2 – predicts nonsurvival
- 400 – 500 mm Hg -> survival uncertain
- < 400 mm Hg -> Better prognosis
II Bohm’ index
☛ Ventilatory index -> Mean airway pressure X RR
☛ Paco2 < 40 mm Hg VI < 1000 -> Always survive
☛ Paco2 > 50mm Hg VI < 1000 -> usually dieS
☛ Paco2 < 40 mmHg VI > 1000 -> usually die
III Echocardiography, pulmonary angiography , cardiac catheterization
- Tachypnea, absent heart sound in left side of chest.
- Scaphoid abdomen, barrd chast
- X – ray chart -> Gas filled bowel in hemithorax
- Radiopaque dye the narogastic tube delinetes the bowel in chest .
- Precordial / esophageal stethoscope
- Pulse oximeter above or below nipple for preductal & postductal SpO2
- Acid –base status
- Invasive BP monitoring, Rt radial Arterial monitoring for preductal PaO2 .
- CVP monitoring
- monitoring – esophagial ,rectal
- Surgical repair is not an emergency unless the contests of hernia are incarcerated.
- Correction of fluid deficit ,acidosis, improved ventilation & ECMO maintenance for indicated new born is necessary
- Lung function improves within 7- 10 days.
- Pt not improve an ECMO or with all the resuscitation X 3 wks have bad prognosis
Pre – operative Management
- Assessment of associated anomalies.
- Maintenance of Normothermia , environmental 30- 40 c.
- ABC, CBC , sr. electrolytes ,blood sugar, blood grooping and cross matching
- Venous access secured in upper limb, central various line through femoral or umbilical vein. Neck veins preserved for ECMO .
- Use of vasodilators – tolazoline , NO ,Prostacyclin , dipyridamole to decrese pulmonary HTN .
- Minimize sympathetic discharge by high dose opioids.
- Nasogastric suction for gastric decompression.
- Transport to OT with O2 supplementation or ET tube in place with manual ventilation.
- Infant in semi – sitting position warmed with warming device , humidified inspired gases & warmed fluid at 37’c .
- Pre –oxygenation with 100 % O2
- Pre – medication with atropine 20 µg/ kg
- High dose opioid to decrees sympathetic discharge
- Awake intubation can be doe
- Alternatively halothane/ sevoflurone with O2 on spontaneous ventilation , N2o avoided to avoid resp. embarrassment
- Bag – mark ventilation & resp. Gastric distention & resp. embarrassment.
- Gental hand ventilation is preferred to avoid ipsilateral or contralateral is preumothorax.
- Anaesthesia is maintained with 100 % O2 with volatile agent and fentanil 1-3 µg/kg
- in shock is maintained on O2 supplementation & non depolarizing muscle relaxants.
- Inhalational agent, opioids and NMB’s are added in titrated doses.
- Pancuronioum, Vecuronium Or Atracunium can be used.
- Low pressure < 20 mm Hg & high RR 60- 120/ min to achieve hypocarbia & keep the Ph between 7.55 -7.60 & maintain PaCo2 between 25-30 mm Hg .
Management of pul HTN
Factor causing in PvR
- Deficiency of surfactant
- Ventilator induced lung injury
- Flutuating pulmonary blood volume.
I. Continue ventilation in the ICU with fentanyl 3µg/kg ,pancuronium 0.1 mg /kg/hr to blunt autonomic cardiovascular response.
II. Minimize endotracheal suction to avoid hypoxia
III. Hyperventilate with low tidal volume, high RR to maintain hypocarbia & Ph 7.55- 7.60 to decrease PVR
IV. Restrict fluid 2-4 ml/kg/hr.
V. Administer pharmacologic pulmonary vasodilator like morphine, chlopromazine, PGE, Inhaled NO
VI. Sever pulmonary hypoplasia with refractory pulmonary HTN with arterial O2 saturation < 50mmHg with fio2 needs ECMO therapy
VIII. High frequency oscillatory ventilation to improved ventilation.
- Correction of pre – op deficit.
- Maintenance fluid with 1/2 strength Ns + 5% D 4ml/ kg/hr.
- Intra-op & 3rd space loss replaced with RV or saline 6-8 ml/kg/hr.
- Blood loss replaced with 3 ml of crystalloid, 1 ml of 5 % Albumin / 1 ml of whole blood or 0.5 ml of RBC for each ml of loss.
Post –op Management
- Decision of Post- op ventilation should be taken electively.
- FiO2 adjusted to maintain Po2 150mm Hg.
- Child is weaned off slowly 48- 72 hrs to avoid the honeymoon phase i.e. . Early smooth course followed by development of pulmonary Vasoconstriction & lethal persistent pulmonary HTN , hypercarbia & acidosis
- Do not extubate the child till the child is fully awake, maintaining saturation of 100% & rhythmically open the eyes.
Mortality Depends Upon
- Reappearance of fetal circulation
- Pulmonary Hypoplasia
- Associated congenital anomalies.
- Pre –op Preparation