Respiratory mechanics, ventilator-associated pneumonia and outcomes in intensive care unit.

Aim: To evaluate the predictive capability of respiratory mechanics for the development of ventilator-associated pneumonia (VAP) and mortality in the intensive care unit (ICU) of a hospital in southern Brazil.

Methods: A cohort study was conducted between, involving a sample of 120 individuals. Static measurements of compliance and resistance of the respiratory system in pressure-controlled ventilation (PCV) and volume-controlled ventilation (VCV) modes in the 1 and 5 days of hospitalization were performed to monitor respiratory mechanics. The severity of the patients' illness was quantified by the Acute Physiology and Chronic Health Evaluation II (APACHE II). The diagnosis of VAP was made based on clinical, radiological and laboratory parameters.

Results: The significant associations found for the development of VAP were APACHE II scores above the average ( = 0.016), duration of MV ( = 0.001) and ICU length of stay above the average ( = 0.003), male gender ( = 0.004), and worsening of respiratory resistance in PCV mode ( = 0.010). Age above the average ( < 0.001), low level of oxygenation on day 1 ( = 0.003) and day 5 ( = 0.004) and low lung compliance during VCV on day 1 ( = 0.032) were associated with death as the outcome.

Conclusion: The worsening of airway resistance in PCV mode indicated the possibility of early diagnosis of VAP. Low lung compliance during VCV and low oxygenation index were death-related prognostic indicators.