Evaluation and Management of Elevated Diaphragm
- Elevated diaphragm is a common finding in athoracic surgery practice.
- Clinical key symptoms are dyspnea and orthopnea.
- Complete diagnostic workup is crucial in treatment planning.
- Surgery yields good results in carefully selected patients
- Minimally invasive techniques gain increasing importance
When discussing the evaluation and management of diaphragmatic elevation, it is necessary to distinguish between congenital conditions of diaphragmatic eventration or diaphragmatic hernias and acquired elevation of the diaphragm. Congenital diaphragmatic pathologies are discussed in separate chapters; this chapter focuses on acquired conditions in which patients present with an elevated diaphragm (Table 1).
Phrenic nerve palsy
Neuromuscular disorders (quadriplegia, multiple sclerosis, amyotrophic lateral sclerosis, Guillain-Barré syndrome, Eaton-Lambert syndrome, myasthenia gravis, muscular dystrophy, steroid myopathy, alcohol myopathy, rhabdomyolysis)
Connective tissue disease leading to pulmonary fibrosis (rheumatoid arthritis, scleroderma, ankylosing spondylitis) or diaphragmatic weakness (systemic lupus erythematosus, polymyositis)
Endocrine and metabolic diseases (hypothyroidism, hyperthyroidism, Cushing’s syndrome, low potassium or phosphate or magnesium, metabolic alkalosis)
In most adult patients, elevation of the diaphragm is primarily detected on chest radiography. Patients are often asymptomatic or present with only mild symptoms. Further confirmation and evaluation of the underlying mechanism may be gained by computed tomography (CT), ultrasonography, or, in rare cases, magnetic resonance imaging (MRI); MRI is, however, useful in detecting paradoxical motion (Iwasawa et al, 2002).,, The underlying pathologies for unilateral or bilateral diaphragmatic elevation encompass a wide spectrum. The cause may be supradiaphragmatic, diaphragmatic, or subdiaphragmatic. Frequently, the exact cause of an elevated diaphragm is difficult to determine even after complete surgical exploration. It remains a point of discussion in the literature whether an underlying occult malignant process is a likely cause.
The main symptoms of an elevated diaphragm are respiratory problems. The underlying mechanism is a restrictive breathing pattern. The severity obviously depends on the degree of diaphragmatic elevation. In addition to restriction, various degrees of compressive atelectasis with decreased ventilation and perfusion in the affected lung base have been described. Another important factor influencing respiratory function is the paradoxical movement of a paralyzed diaphragm. There is paradoxical deflation of the lung during inspiration, caused by elevation of the diaphragm, and during expiration there is paradoxical inflation of the lung, resulting in rebreathing of dead air space. The normal diaphragm creates a negative intrapleural pressure, which is absent in a diseased elevated diaphragm, resulting in paradoxical movement.
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