Eventration
or Paralysis
Some authors have used eventration as a synonym for diaphragmatic paralysis,
while some have made distinctions between them. Both of them have the
same clinical and radiological appearance, and paralysis which do not
resolve can cause atrophy of the muscle and eventration.
Pathophysiology
Unilateral eventration and paralysis have the same effect on ventilation.
Diaphragmatic weakness causes a decrease in ventilation and oxygenation.
This can be aggravated by abdominal pressure in the supine position
and by a small caliber bronchial tree. A flexible chest wall, weak intercostal
and accessory muscles, and mobile mediastinum add to this effect.
Clinical
presentation
–
Incidence of eventration at birth and infancy 1/1400-1/13000 (both congenital
and birth trauma)
–
Incidence post cardiac surgery paralysis is 0.5-1.5%
–
Most
paralysis occurs on the right side.
–
75%
have ipsilateral Erb's palsy.
Signs
and symptoms
Depending on the respiratory compromise:
1. Tachypnea, decreased breath sounds on the affected side and cyanosis
2. The "belly-dancer's sign": umbilicus shifts up and to the side of
the paralyzed diaphragm during inspiration.
3. Unexplained severe respiratory distress needing ventilatory support
4. Erb's palsy
5. Recurrent pneumonia
6. Failure to thrive, nausea and vomiting
Differential
diagnosis
1. Congenital diaphragmatic hernia.
2. Non paralytic eventration
3. Congenital heart disease (CHD): If presenting with dyspnea and cyanosis
within hours of birth then it may be confused with CHD.
4. Intracranial hemorrhage.
Investigations
1. CXR: the affected hemi-diaphragm is elevated in relation to the normal
side.
2. Fluoroscopy in spontaneously breathing confirms immobility or paradoxical
motion of the affected side during inspiration.
3. Ultrasound: proved feasible and useful in evaluating diaphragmatic
motion. It may replace fluoroscopy (Gerocovich et al 2001.
4. Phrenic nerve conduction time: gives a direct evaluation of function
and integrity.
5. EMG: assess during spontaneous breathing
6. Stimulation of Phrenic nerve to see the response of the diaphragm.
If it contracts adequately it suggests a favorable prognosis
7. Measurement of transdiaphragmaitc pressure (Pdi) also gives an idea
of the strength of the diaphragm.
Management
Will depend on the degree of respiratory compromise, likelihood of recovery,
and age of the child.
1. Intubation and positive pressure ventilation in severe cases.
2. Continuous distending airway pressure during spontaneous breathing
(CPAP,BIPAP)
3. Tracheostomy for prolonged ventilatory support.
4. Diaphragmatic plication.
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