Association of personalized "PEEP" optimization based on driving pressure with recruitment-inflation rate in patients on mechanical ventilator support in intensive care unit

Patients followed up in intensive care units (ICU) require mechanical ventilation to a large extent. End-expiratory positive pressure (PEEP) titration is of great importance to maintain the physiology of lung mechanics in mechanically ventilated patients. Today, the optimal method for this titration is still under investigation. In our study, we aimed to investigate the relationship between personalized "PEEP" optimization based on driver pressure and recruitment-inflation ratio (R/I) in patients receiving mechanical ventilator support in intensive care unit. After Ethics Committee approval, 30 adult patients hospitalized in intensive care units and undergoing invasive mechanical ventilation were included in the study. Functional residual capacity (FRC) and end-exhaled lung volume (EELV) were measured using a decreasing PEEP titration procedure (5 cmH2O) and multiple nitrogen flushing technique. Oxygenation was evaluated by arterial blood gas at each PEEP level. The highest compliance value and the lowest drive pressure and EELV values were reached at 5 cmH2O PEEP level. The highest values of P/F ratio as one of the oxygenation indicators were measured at 20 cmH2O PEEP level. At the PEEP levels we studied, the same PEEP selection could not be achieved according to the R/I ratio defined for lung recruitability with the clinical PEEP selected according to the calculated driver pressure. In conclusion, sufficient and strong evidence has not been obtained for the use of the R/I ratio alone in clinical practice. More studies are needed for this.