The purpose of this study is to determine whether a computer-driven system (Smartcare/PS) decreases weaning duration from mechanical ventilation when compared to usual care in children.

Baseline data: All subjects included into this RCT will undergo routine examination upon admission to the hospital. These examinations include physical, medical/medication history (on the last year for medical history and the last 3 months for medication history (if available), vital signs, radiologic data and laboratory tests.

Intervention: A pre-inclusion test (pressure support test) with a level of pressure support of ± 5 cmH2O of the P plateau, but no greater than 30 cmH2O (pressure-support level plus positive end-expiratory pressure), is performed to evaluate the patient's tolerance of this ventilation mode; the test is repeated daily until positive. The test could be stopped before 30 minutes if the patient showed evidence of respiratory distress (respiratory rate > 40 breaths per minute and FiO2 > 60% in order to obtain pulse oxymetry ≥ 95%). The test is considered positive when, after 30 minutes, the patient remained clinically stable with a respiratory rate lower than 40 breaths per minute and an expiratory tidal volume higher than 6 ml per kilogram of body weight within the authorized pressure-support range, with pulse oxymetry no lower than 95 percent when the fraction of inspired oxygen was no greater than 60 percent. When the pressure-support test is positive, the patient is randomized either to Arm 1 where the intervention is weaning with the support of Smartcare/PS or to Arm 2 where the intervention is weaning based on usual care. Both group are ventilated with the same ventilator: Evita XL.

Inclusion Criteria:

• The attending physician thinks that the patient will be able to breathe spontaneously or the patients is already breathing spontaneously.
• No vasopressor or inotropic medication, unless the patient is receiving some digitalin or small doses of dopamine (< 5 µg/kg/min)
• Slight or no endotracheal tube gas-leakage ([Vti - Vte]/Vti ≤ 20%)
• Mechanical ventilation with a plateau pressure ≤ 25 cmH2O over PEEP
• PEEP ≤ 8 cmH2O
• FiO2 ≤ 60% in order to obtain pulse oxymetry ≥ 95%
• PaCO2 < 70 mmHg on the last blood gases
• Extubation not expected the day of inclusion

Exclusion Criteria:

• N/A