1 Diaphragmatic Function, Diaphragmatic paralysis, and Eventration of the Diaphragm
2 With quite breathing, the diaphragm accounts about 75 to 80% of ventilation. The vertical movement of the diaphragm is 1 to 2 cm during quite breathing and 6 to 7 cm during deep breathing. Each cm of vertical movement contributes 300 to 400 ml of air during normal breathing.
3 The diaphragm comprise 2 parts: costal and crural portions. The costal portion is thinner and the crural portion is thicker. Both portions are innervated by the phrenic nerve. The costal portion flatten the diaphragm and lift the rib. The crural portion causes downward placement of the diaphragm( less effective in breathing.)
4 PARALYSIS OF THE DIAPHRAGM In the adult, unilateral diaphragmatic paralysis does not cause significant respiratory embarrassment. But 20 to 30% of reduction of vital capacity and total lung capacity occurs. Fackler et al reported these lung volumes become normal 6 months later.
5 PARALYSIS OF THE DIAPHRAGM In normal adults, bilateral diaphragmatic paralysis may be tolerated. However, excessive movement of accessory muscles of respiration may be seen.
6 PARALYSIS OF THE DIAPHRAGM In infants and young children, unilateral diaphragmatic paralysis may cause severe respiratory embarrassment and mechanical ventilation is indicated. Bilateral diaphragmatic paralysis is more lethal. Paradoxical movement of the lower rib cage can be seen in these infants and young children.
7 PARALYSIS OF THE DIAPHRAGM When these patients are in the lateral decubitus position with paralyzed diaphragm leaf up, inward movement of the subcostal area of the upper abdomen can be seen.
8 PARALYSIS OF THE DIAPHRAGM Paralysis of the hemidiaphragm may be seen by elevation the diaphragm leaf on CXR. Sniff test: sudden inspiratory movement causes the paralyzed hemidiaphragm to ascend by the fluoroscopic observation. In patients with mechanical ventilation, electrophysiologic evaluation of the phrenic nerve is needed.
9 Etiology of Diaphragmatic Paralysis In infants, most unilateral diaphragmatic paralysis are caused by injury of the phrenic nerve during a cardiac procedure. The Mustard and Glenn procedures had the highest incidences. Birth trauma and removal of the mediastinal tumor are another causes.
10 Etiology of Diaphragmatic Paralysis In adults, most injury of the phrenic nerve during a cardiac procedure is caused by the use of topical hypothermia with ice slush. The left side is usually the involved nerve. The cold injury can be prevented by avoidance of entering the pleural space and inflation of the lung.
11 Etiology of Diaphragmatic Paralysis Helps et al reported a right thoracotomy with a low submammary incision had higher incidence of phrenic nerve injury than a midline sternal approach in the repair of secundum atrial defect
12 Etiology of Diaphragmatic Paralysis Other causes of diaphragmatic paralysis are tumor, mediastinotomy, resection in the thorax and the neck, and even placement of a subclavian or jugular vein catheter or electrode. Idiopathic paralysis of the diaphragm is not uncommon and it is the result of viral infection. The paralysis is often unilateral.
13 Management of Diaphragmatic Paralysis In infants and young children, mechanical ventilation is the initial treatment with the involved side down. If continued support is required beyond 2 weeks, operative plication is indicated. The plication does not require muscle resection.
14 Management of Diaphragmatic Paralysis The plication can immobilize the paralyzed diaphragm in the flat position to reduce the paradoxic movement with associated shift of the mediastinum to the contralateral side. In adults and children older than 2 years, conservative treatment is often indicated. Celli et al reported the use of intermittent external negative-positive pressure to treat idiopathic paralysis of the diaphragm.
15 Therapy Use of the Phrenic Nerve Paralysis Therapeutic temporary paralysis of a phrenic nerve has been used to treat TB in the past. It can obtained by percutaneous infiltration about the nerve trunk in the neck with local anesthetic. Additional elevation of the paralyzed diaphragm can be obtained by a temporary pneumoperitoneum.
16 EVENTRATION OF THE DIAPHRAGM It is a rare anomaly and the cause is not known completely. Eventration of a newborn is a true congenital defect and severe cardiorespiratory distress may occur because of associated hypoplasia of the lung of the same side. After the newborn is stable, operative correction is indicated.
17 EVENTRATION OF THE DIAPHRAGM The surgery is usually through a thoracic approach. In adults and old children, eventration is caused by acquired complete or incomplete paralysis of the diaphragm. Localized eventration, usually on the right side, with protrusion of the liver, does not require surgery.
18 EVENTRATION OF THE DIAPHRAGM With a major hernia or a complete eventration, the patient may have cardiorespiratory or GI symptoms. Surgery is indicated for symptomatic older patients.
19 EVENTRATION OF THE DIAPHRAGM A thoracic approach with entering through the 8 th ICS is preferred. After entering the pleural space, the the diaphragm is repaired by plication. The 2 nd method is by incision of the leaf and repair with silks or other nonabsorbable sutures interruptedly. However, plication is preferred. Mouroux et al reported video-assisted thoracoscopic approach.