Introduction The optimal positive end-expiratory pressure (PEEP) in acute respiratory distress syndrome (ARDS) remains uncertain. This study compared the PEEP levels using five distinct titration methods to assess potential ventilator-induced lung injury (VILI). Methods This study included 21 patients with moderate to severe ARDS who were monitored using esophageal balloon manometry and electrical impedance tomography (EIT). A recruitment maneuver followed by decremental PEEP titration was performed. Optimal PEEP (OP) was assessed using five criteria: highest respiratory system compliance (C RS), highest lung compliance (C L), end-expiratory transpulmonary pressure (P tpₑedirect) ≥ 0 cm H 2 O, elastance-derived end-inspiratory transpulmonary pressure (P tpₑiderived) ≤ 25 cm H 2 O, and EIT-based analysis balancing the degree of overdistention and lung collapse. Results Significant differences in OP were observed across the methods (p = 0. 001): C RS 8. 0 cmH₂O (8. 0, 13. 9) ; C L 9. 8 cmH₂O (8. 0, 14. 0) ; P tpₑedirect ≥ 0 cmH₂O 14. 0 cm H₂O (11. 9, 17. 9) ; P tpₑiderived ≤ 25 cmH₂O 12. 0 cmH₂O (10. 0, 13. 9) ; EIT balancing the degree of overdistention and lung collapse 13. 01 cmH₂O (9. 88, 14. 78). The OP guided by P tpₑedirect of ≥ 0 cm H 2 O is significantly higher than OP by the highest C RS (p = 0. 001) and the highest C L (p = 0. 002), and met the overdistension criteria, namely plateau pressure 30 cm H 2 O and the highest percentage of overdistension by EIT. The PEEP guided by C RS had a higher potential risk of lung collapse, reflected by the negative value of P tpₑedirect and a higher percentage of lung collapse by EIT. Conclusion Transpulmonary pressure-guided PEEP titration yielded higher PEEP levels, while C RS -guided PEEP was lower and associated with a higher risk of collapse. Overdistension and collapse varied with the chosen PEEP method. In patients with moderate to severe ARDS, OP can vary depending on the method of assessment.
Sutherasan et al. (Fri,) studied this question.