<unk>  was first suggested by Steurtz, in 1911 during a simple phrenicotomy for treatment of lung disease.<unk>  may be classified according to involvement of leaflets into unilateral or bilateral. It is thought that<unk>  is the result of<unk>  of cervical nerve roots( C3-C5). Common causes of unilateral<unk>  include idiopathic, phrenic nerve injury in cardiac surgery and viral infection. Common causes of bilateral<unk>  include idiopathic, cervical spinal cord disease and motor neuron disease. Unilateral<unk>  must be differentiated from eventration of the diaphragm. Eventration of the diaphragm is an abnormal elevation of the hemidiaphragm. Bilateral<unk>  must be differentiated from other diseases that cause elevation of the diaphragm such as pleural adhesions, subpulmonic effusions, obesity, ascites, abdominal organomegaly and ileus. Other differential diagnosis are dermatomyositis, polymyositis, rib fracture, pleural effusions, amyotrophic lateral sclerosis.The incidence of<unk>  is unknown, but incidence of<unk>  after cardiac surgery is approximately 30,000 to 75,000 per 100,000 individuals. Prevalence of<unk>  after cardiac surgery is 1,600 per 100,000 in children. The most potent risk factor in the development of<unk>  is cooling or stretching in cardiac surgery. Common complication of<unk>  includes severe pulmonary dysfunction in bilateral<unk> . Studies of choice for unilateral<unk>  include upright chest radiograph and fluoroscopic sniff test. Studies of choice for bilateral<unk>  include measurement of transdiaphragmatic pressure (Pdi). The majority of patients with unilateral<unk>  are asymptomatic.  Dyspnea in supine position and orthopnea are common symptoms of bilateral<unk> . Laboratory findings consistent with the diagnosis of<unk>  include reduced oxygen saturation in the supine position in unilateral and bilateral<unk>  and elevated arterial partial pressure of carbon dioxide (PaCO2) in bilateral<unk> . An x-ray and ultrasound are helpful in the diagnosis of<unk> . No treatment is required for unilateral<unk>  because most patients are asymptomatic. In bilateral<unk>  treatment options are ventilatory support and diaphragmatic pacing. Surgery is usually reserved for patients with either dyspnea in strenous physical activity and patients with underlying severe pulmonary disease. Surgical plication of the involved hemidiaphragm can be considered for unilateral<unk> . surgery in bilateral<unk>  can be done via neurolysis and nerve grafting.
Diaphragmatic paralysis
Tracheal deviation
Trapped lung
Vocal cord paresis
Diaphragmatic rupture
Urinothorax
Flail chest
Diaphragmatic eventration