Diagnosis of diaphragmatic dysfunction.

Diaphragmatic dysfunction is an important entity, as it can cause severe dyspnea, ventilation-perfusion abnormalities, and ventilatory failure. The most frequent and important dysfunctions are diaphragmatic weakness, incoordination between the diaphragm and other respiratory muscles, fatigue, and paralysis. Methods for the diagnosis of dysfunction are reviewed and specific dysfunctions are briefly discussed with methods for their evaluation.