Mediastinal shift: a sign of significant clinical and radiological importance in diagnosis of malignant pleural effusion
Mediastinal shift (upper and lower) is a clinical and radiological marker of significant importance, which at times helps to determine the aetiological cause of the underlying pathology. Tracheal shift is an indicator of upper mediastinal shift, while a shift in the position of the heart indicates a lower mediastinal shift. Since the pleural cavity is confined by the rib cage, in case of a moderately large pleural effusion, the structures in the thoracic cavity normally get ‘pushed’ to the opposite side resulting in a shift of the upper and lower mediastinum. This is clinically and radiologically detected by a shift in the trachea and heart to the side opposite to the pleural effusion. This is commonly seen in pleural effusions resulting from tuberculosis or other infections. However, in some cases even a large pleural effusion fails to shift the mediastinum to the opposite side. In fact, in some cases, the trachea and heart are observed to be central or even shifted to the same side as the effusion. This finding is of immense importance as it is a clinical indicator of a more serious condition which needs prompt diagnosis and urgent management. (copied from article).
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