The hypothesis of the present study is that the use of Continuous Positive Airway Pressure (CPAP) plus PS can accelerate the weaning process and, consequently, shorten the MV. This multicenter, pragmatic clinical trial aims to compare the use of CPAP + PS versus SIMV + PS as a method for ventilatory weaning of children, emphasizing the duration of the process. There are no similar studies in the world.

Mechanical ventilation (MV) is a widely used practice among Pediatric Intensive Care Units (PICUs) throughout the world. Data from multicenter studies reveal rates ranging from 20% to 64% use, lasting about 5 to 6 days.

The practice of using artificial methods to provide respiratory care is considered a revolution in the care of critically ill patients, reducing their morbidity and mortality. On the other hand, it is widely known that these tools bring with it a myriad of possible complications, such as Health Care-Associated Pneumonia, upper and lower airway injuries, risks related to sedation, and cardiovascular instability. Therefore, it is indispensable to interrupt the MV as soon as possible.

When is spent a lot of time recognizing that the MV is no longer essential, is increased the risks and costs (up to $ 2,000 a day), and is failed the good medical practice. Currently, the duration of weaning consumes about 40% of the total MV time. This depends on many factors, such as fluid balance, positive end expiratory pressure (PEEP), sedation, pulmonary hypertension and diaphragm function, among others.

Studies have shown that the implementation of a weaning protocol reduces its duration and, consequently, ventilation in children. There are numerous known weaning techniques, however, the most commonly used approach is the progressive reduction of ventilatory support already in use, maintaining the same modes and reducing the parameters. Some professionals choose synchronized intermittent mandatory ventilation (SIMV), reducing respiratory rate, with or without Supplementary Pressure (PS) association. Others prefer to perform daily extubation readiness tests (ERT) or to switch spontaneous breathing methods with full-support ventilation for respiratory muscle training, this practice is more common in adult ICUs. Exhorted by recommendations for mechanical ventilation of critically ill children at the 2017 pediatric mechanical ventilation consensus conference (PEMVECC), who concluded with strong agreement that there is insufficient data to recommend the method for weaning the investigators decided to study the assertive.

Inclusion Criteria:

• Children who underwent mechanical ventilation for at least 24 hours in one of the participant PICUs

Exclusion Criteria:

• Children dependent on mechanical ventilation and / or chronically supplemental oxygen;
• Children with do not resuscitation order (DNR)
• Children with neurological and neuromuscular disorders that may interfere with MV;
• Children with chronic lung diseases (such as cystic fibrosis, bronchopulmonary dysplasia, chronic obstructive pulmonary disease, with the exception of asthma);
• Children transferred from another PICU not included in the trial and whose weaning has already begun;
• Children whose cannulae have air leakage higher of 25% of inspiratory flow, without indication for cannula replacement.