Congenital malformations - Edocr

156 PART IV RESPIRATORY MALFORMATIONS
In cases of prenatally diagnosed CDH, the
infant should immediately undergo endotracheal
intubation upon delivery to facilitate mechanical
ventilation. The bag and mask ventilation
of these infants should be avoided and a
nasogastric tube should be inserted to prevent
gaseous distention of the bowel. Pre- and postductal
saturations should be monitored for evidence
of right to left ductal shunting secondary
to pulmonary hypertension. An arterial blood
sample should be obtained as soon as possible
to determine ventilation, oxygenation, and acid
base status. A chest x-ray should be obtained to
evaluate for the side and extent of intestinal herniation.
Infants who present with severe respiratory
distress, severe pulmonary hypertension
complicated by persistent hypoxemia and severe
hypercapnia, may be candidates for ECMO
and should be transferred, when stable, to facilities
with ECMO capabilities.
Based on observations of decreased surfactant
in animal models of CDH, several authors
have reported the use of exogenous surfactant
in infants with CDH. 27,28 According to Doyle
and Lally, numerous reports using data from the
CDH registry have been presented on surfactant
use in infants with CDH, however, investigators
have failed to demonstrate any benefit with surfactant
use. 29 The use of surfactant has been
studied in both term and preterm infants with CDH
and these studies have suggested evidence of harm
with surfactant use and no evidence of any benefit.
29,30 Therefore, routine use of exogenous surfactant
cannot be recommended for these infants.
Nitric oxide, when used as initial therapy for
infants with CDH and severe respiratory failure
does not appear to improve overall survival or
reduce the need for ECMO. 31 However, it may
be useful in patients with CDH later in their hospital
course after the surgical repair of the diaphragmatic
defect as many infants with CDH
have pulmonary hypertension that may last for
months or longer. 32
After birth, surgical repair of the defect is the
primary goal of treatment but the optimal timing
of surgery remains unclear. 25 During the
1980s, emergency surgery for CDH was thought
to be the rule rather than the exception. When
it was discovered that the pulmonary hypertension
and pulmonary hypoplasia were responsible
for the high mortality and morbidity rates,
delayed surgical approach was introduced. Diaphragm
reconstruction with a prosthetic material,
such as Gortex is the preferred surgical procedure.
25 Postoperative management involves close
attention to ventilator management with the goal
of minimizing barotrauma, ensuring adequate
oxygenation while minimizing hypercarbia and
acidosis. Monitoring of the infants’ fluid status,
cardiovascular function, nutrition, and pain management
is also imperative.
While CDH remains a high-risk disease, current
management strategies have resulted in survivals
of 85–90% in some centers. 31 However,
the overall mortality rate remains at 50% with
significant morbidity in survivors. 33 At present
the best prognostic indicators for CDH are the
presence or absence of liver herniation into the
chest across the diaphragmatic defect and prenatal
sonographic measurement of lung/head
ratio. 26,34 Prognosis is poor when the liver is intrathoracic
and LHR is less than 1. 35 Additional
findings associated with a poor prognosis
include: the presence of polyhydramnios, the
presence of CDH at less than 25 weeks estimated
gestational age, and the presence of associated
chromosomal or congenital anomalies. 36 Other
factors associated with a significant decrease in
survival rate are: initial PCO 2 >50, PO 2