Poor oxygenation results from a combination of alveolar hypoventilation, pulmonary
hypoperfusion and potential lack of surfactant.
Management
Early recognition followed by aggressive proactive management is crucial to
outcome.
Antenatal management: Diagnosis by prenatal ultrasound educates the parents
when planning for delivery at an experienced center. In general, the earlier in gestation
CDH is diagnosed, the worse the prognosis. Also right-sided lesions tend to be worse
than left sided lesions.
Several attempts have been made to correlate prenatal imaging with postnatal
outcome The lung-to head ratio (LHR) was first desribed in 1996 correlates a two
dimensional lung size in a fetus in relation to a growth standard such as the head
circumference. The LHR is measured at 24-26 weeks in a left sided CDH baby.
The lung area contralateral to the CDH was originally obtained by taking the
product of the longest two perpendicular linear measurements of the lung measured at
the level of the 4-chamber view of the heart on a transverse scan of the fetal thorax.
The product is divided by the head circumference (HC) to obtain the LHR.
- If the LHR is 1 or less, the prognosis is poor. The prognosis is poorer still if the liver is
in the thorax. Such patients may be candidates for prenatal intervention. (The
University of California, San Francisco, http://fetus.ucsfmedicalcenter.org/cdh/)) - If the LHR is between 1.0 to 1.4 , ECMO)is often needed.