Mechanical ventilation (MV) is a vital support tool for critically ill patients. However, it may present several adverse effects, such as the development of cognitive and psychopathological alterations. Patient-ventilator asynchronies occur frequently since the beginning of the MV. These asynchronies are associated with poor clinical outcome and could be responsible for the neuronal changes causing these alterations. The objective of this project is to analyze the influence of patient-ventilation asynchronies in the development of long-term cognitive/psychopathological impairments and to explore the molecular mechanisms that could explain of these alterations. An exploratory, observational, multicenter, non-interventionist study will be performed in 150 ICU patients. The continuous recording of asynchronies and other clinical variables during ICU stay and the results of neuropsychological assessments will enable to identify clinical clusters associated with cognitive/psychopathological impairments.

MV parameters, as well as other physiological variables, will be monitorized during the ICU stay in all patients. A neurocognitive and psychopathological assessment will be administed in all patients at 1-month and 1-year follow up.

After data collection, an asynchronies index will be calculated. A clusters analysis, based on clinical variables and asynchronies index, will be performed. The relationship between patients' clusters and the neuropsychological/ psychopathological data will be analized.

CLINICAL STUDY Univariate descriptive analysis: for quantitative variables the mean, standard deviation, percentiles 25, 50 and 75, minimum is calculated and maximum. For qualitative variables, the absolute and relative frequencies were calculated. Population interval will be estimated at 95% confidence level.

Multivariate analysis: cluster analysis, with the intention to investigate possible associations of individuals and characterization of the profile of each cluster. Comparison of standardized scores (z) of the neuropsychological variables and asynchronies index between clusters will be carried out by parametric or nonparametric techniques, as more appropriate.

Association of asynchrony with the neuropsychological variables: conditional logistic regression (case-control) of the scores of neuropsychological variables (dichotomized) versus asynchronies index will be performed, controlling for confounding covariates or factors that may have a modifier effect. The multivariate case-control matching will be performed by the method of propensity score or by genetic algorithms. The odds ratio and confidence interval of 95% was estimated.

Sample size: has been used rule of thumb for logistic regression models include between 10-15 cases per covariate. In this case, the sample will consist of 150 patients.

Inclusion Criteria:

• Aged 18 to 80 years old.
• No neurological disease
• No evidence of COPD.
• Patients within the following 24 hours at endotracheal intubation and who are clinically expected to receive > 72 hours of mechanical ventilation

Exclusion Criteria:

• No authorization of the family or patient inclusion.
• Age outside the limits.
• Patients with prior neurological disease or focal brain damage prior to admission to the ICU
• Patients with serious psychiatric illness or mental retardation.
• Time monitoring of asynchrony < 80% of the total duration of mechanical ventilation.
• Patients who develop secondary complications (infections, stroke, brain damage or structural TC acquired) after discharge from ICU (during hospital stay) that could compromise the results of neuropsychological assessment.
• Patients with moderate to severe cognitive impairment previous to ICU stay (Short form IQCODE > 57 score)

ICU patients undergoing mechanical ventilation and monitored with and advanced continuous monitoring system.