[Evaluation of the strength, reserve and fatigue of the respiratory muscles in weaning from mechanical ventilation].

Beyond a certain threshold of intensity and duration of contraction the respiratory muscles are prone to fatigue, and this process may preclude weaning from mechanical ventilation. Respiratory muscle fatigue can be detected by several techniques (maximal voluntary pressures, electrical stimulation, electromyography, muscle relaxation rate, analysis of breathing movements, occlusion pressure). The most reliable techniques are complex, but new noninvasive tests are presently under development.