Introduction: Patients on mechanical ventilation suffer alterations in the viscoelastic characteristics of the mucus due to changes in the humidity and temperature of the inhaled air and in the respiratory volumes and flows. The literature has pointed out the use of mechanical ventilators as a tool for mobilizing secretions and closed-system aspiration associated with expiratory pause has been shown to be effective in mobilizing secretions. Objectives: To assess whether there is a difference in the mass of aspirated secretion with the application of the expiratory pause during aspiration. Methods: A crossover, randomized study. Applied to children aged 0 to 5 years and 11 months who are intubated for 24 hours with orotracheal tubes or tracheostomy. There will be an exclusion of patients who present with undrained pneumothorax, cranial hypertension or any other clinical situation that has a clinical contraindication to aspiration and patients whose parents do not agree to participate in the study. The technique will be during aspiration in the tube with where to apply or not the expiratory pause on the mechanical ventilator. This secretion will be weighed so that there is fidelity in the results.

A prospective, crossover, randomized clinical study will be carried out in the Pediatric ICU of Hospital Israelite Albert Einstein.

Inclusion Criteria:

• Patients aged 0 to 5 years and 11 months who have been on invasive mechanical ventilation for more than 24 hours through an orotracheal cannula or tracheostomy will be included in the study.

Exclusion Criteria:

• Patients who present with undrained pneumothorax, cranial hypertension or any other clinical situation that has a clinical contraindication to aspiration and patients whose parents do not agree to participate in the study will be excluded from the study.

the results of the study can be requested by the person responsible for the patient and these will be sent by emial