In the critically patient bed rest and immobilization are some of the responsable of the development of respiratory complications. Early physical exercise is a tool to prevent respiratory complications as lost of respiratory muscle strength, decrease in functional residual capacity and hypoxemia improving oxygenation.

New technology as electrical impedance tomography (EIT) are available to visualize changes of regional lung aeration.

The aim of this study is to assess the effect of early physical exercise improving alveolar recruitment and pulmonary ventilation in intensive care unit (ICU) patients, evaluated with EIT.

The ICU patients included at day of evaluation will be evaluated continuously with EIT in different positions. 1) in the supine position (at 30° of inclination), 2) Sitting in chair 3) Active physical exercise 4) And rest in chair after exercise

Inclusion Criteria:

• Patient admitted at the Intensive Care Medical/Surgical Unit of Clinic Saint Luc
• Days of hospitalization between 1 and 10
• Hemodynamically stable
• Patient or family member sign the informed consent

Exclusion Criteria:

• With risk of evisceration
• Therapy withdrawal
• With cardiac devices (Pace Maker)
• Persistent cough
• Patches or open wounds in zone of electrodes
• Presence of high vasopressor medication (noradrenaline > 3 mg/h)
• PEEP > 15 cm H2
• Acute Myocardial Infarction
• Active bleeding
• Intracranial pressure > 20 mm Hg or with major instability