ABSTRACT
Hypothesis: There is no hypoxemia after tracheal aspiration when there is no optimization of O2 pre-aspiration. Aim: To verify, through the assessment of arterial gasometry, if there is a significant difference in the values of SaO2, PaO2 and P/F in patients on ventilatory assistance and septic shock when FiO2 is not kept to 100% after tracheal aspiration. Methodology: a randomized clinical trial-type crossover, with two interventions, one arm, double-blind, phase III. A convenience sample of 27 patients is used by calculation for discrete variables of finite populations. Inclusion criteria: septic shock due to local infection, mechanical ventilation for more than 12 hours, optimal FiO2 <95%, PEEP <24 mmHg. For the statistical analysis we will use the student`s t-test with a significance level of 5% supported by software R version 2.5.1