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Congenital Diaphragmatic Hernia and Diaphragmatic Eventration 293

• A renal ultrasound scan is useful in ruling out any renal abnormalities.
• Fluoroscopy of the diaphragm may help differentiate between even-
tration and CDH in cases that are difficult to distinguish. Ultrasound
of the diaphragm is less sensitive in picking up paradoxical move-
ment than fluoroscopy, and is sometimes false negative.
Management
The most important management is the resuscitation and stabilisation
of the newborn by an experienced neonatologist. If the diagnosis is
suspected, avoid bag and mask positive-pressure ventilation (to avoid
intestinal distention and possible worsening of respiratory compromise).
The management of CDH is a complex one that involves specialist
neonatal ventilatory and cardiovascular support in severe cases. The
4,5
essence of neonatal management can be summarised as follows:
• Prompt endotracheal intubation in the delivery room for respiratory
distress.
• Replogle tube or wide-bore nasogastric tube insertion.
• Chest and abdominal x-ray to confirm diagnosis, assess NGT posi-
tion, and exclude other diagnoses.
• Early measurement of blood gases, repeated at regular intervals to
aid management.
Figure 45.4: Chest and abdominal x-ray of patient showing a right-sided CDH. A
soft tissue shadow is seen in the chest and represents the herniated liver. Also • Surfactant administration, used in some centres in selected cases.
note in this patient the presence of a dilated trachea (dilated radiolucent pouch in • Preductal oxygen saturations maintained at 85–90%.
lower neck/upper chest) as a result of antenatal tracheal occlusion. Remnants of
the balloon used is seen as a radio-dense dot in the left side of the chest. • Minimal ventilation pressures to reduce barotrauma (iatrogenic
injury from ventilation strategies may be significant and should be
minimised).
• Volume resuscitation and vasopressors (dopamine and dobutamine)
often required to maintain systemic blood pressure (BP) and reduce
right-to-left shunting.
• Pulmonary vasodilatation with inhaled nitric oxide and occasionally
other vasodilators (e.g., nitroprusside).
• Consideration of high-frequency oscillatory ventilation when con-
ventional ventilation fails or when peak airway pressures remain
high (>30 cm H O).
2
• Extracorporeal membrane oxygenation (ECMO), which has not
offered consistent beneficial results in most studies. Oxygenation
index (FiO × mean airway pressure × 100/PaO ) can be used to
2 2
predict the need for ECMO in centres where this is offered. An
oxygenation index value of >40 is an indication of severe respira-
tory failure and the need for ECMO.
• Initially not feeding by mouth (but trophic feeding is not strictly
contraindicated in those stabilising with no signs of obstruction).
Reliable central venous access is required for administration of
drugs or fluids and/or parenteral nutrition.
One method used to predict outcome in the postnatal period is
Figure 45.5: Chest X-ray of patient showing a left-sided Morgagni hernia. The a formula developed at the Red Cross Hospital in South Africa,
6
bowel loops are seen overlying the cardiac shadow, and loops can be traced (respiratory rate × PCO × FiO × mean airway pressure/PaO ×
from the abdomen just to the left of the midline 2 2 2
6000), based on the first arterial blood gas obtained on initiation of
resuscitation. A value greater than 5 was used as a cutoff between
Other investigations and their indications are: survivors and nonsurvivors, with 16/16 (100%) of patients above this
• An echocardiogram is useful in evaluating cardiac function (shunt- value dying and 17/20 (85%) below this value surviving. Overall, it had
ing, ejection fraction, cardiac output, and changes with inotropic a 91% predictive value.
support) and in outlining any cardiac anomalies associated with Surgery
CDH (atrial and ventricular septal defects).
Surgery is usually contemplated only in those who stabilise and
• A contrast study may be indicated in cases of suspected Bochdaleck improve on medical management. Stability is indicated by a decreased
hernia that do not have a definitive diagnosis on plain radiograph. ventilatory requirement (transition from high frequency to conven-
A contrast enema or meal with follow through may delineate bowel tional ventilation being a good sign of improvement), decreased
contents in the chest. oxygen requirements, return of haemodynamic stability, and weaning