In addition to conventional chest physiotherapy, inspiratory muscle training will be applied in mechanically ventilated intensive care patients. It is aimed to examine the effects of inspiratory muscle training on respiratory muscle strength, diaphragm thickness, and diaphragm excursion in intubated or tracheostomized patients with mechanical ventilation in the intensive care unit.

Subjects who mechanically ventilated in the intensive care unit will be divided two groups. Study group will recieve inspiratory muscle training in addition to convantional chest physiotherapy. Control group will recieve convantional chest physiotherapy. Training will continue until discharge or until the 21st day of the training. Respiratory muscle strength, diaphragm thickness and diaphragm excursion were measured before training and before discharge.

Inclusion Criteria:

• ≥18 years of age
• hemodynamic stability and alert
• able to spontaneously trigger the ventilator and perform at least one command for activation of respiratory muscles
• required mechanical ventilation support with continuous spontaneous ventilation mode or pressure- or volume-controlled intermittent mandatory ventilation (6 breaths/min) mode
• required pressure support ≤ 15 cmH2O and PEEP ≤ 10 cmH2O
• unable to breathe without support for 72 consecutive hours following the resolution of factors leading to respiratory failure
• FiO2 of 0.5 or less
• PaO2 greater than 60 mmHg and capable of sufficient gas exchange

Exclusion Criteria:

• cooperation disorder
• trauma or deformity related to the thorax that affect respiration
• progressive neuromuscular disease
• excessive bronchial secretion (requiring more than one suctioning per hour)
• need for continued sedative or analgesic agents
• use of home-type mechanical ventilation before admission to the hospital
• cardiac, pulmonary, or other conditions leading to impaired stability
• impaired cooperation, compliance, and motivation