Findings of ventilator-measured P0.1 in assessing respiratory drive in patients with severe ARDS

Background: Providers should adjust the depth of sedation to promote lung-protective ventilation in patients with severe ARDS. This recommendation was based on the assumption that the depth of sedation could be used to assess respiratory drive.

Objective: To assess the association between respiratory drive and sedation in patients with severe ARDS by using ventilator-measured P0.1 and RASS score.

Methods: Loss of spontaneous breathing was observed within 48 h of mechanical ventilation in patients with severe ARDS, and spontaneous breathing returned after 48 hours. P0.1 was measured by ventilator every 12 ± 2 hours, and the RASS score was measured synchronously.

Results: The RASS score was moderately correlated with P0.1 (R𝑆𝑝𝑒𝑎𝑟𝑚𝑎𝑛, 0.570; 95% CI, 0.475 to 0.637; p= 0.00). However, only patients with a RASS score of -5 were considered to have no excessive respiratory drive, but there was a risk for loss of spontaneous breathing. A P0.1 exceeding 3.5 cm H2O in patients with other RASS scores indicated an increase in respiratory drive.

Conclusion: RASS score has little clinical significance in evaluating respiratory drive in severe ARDS. P0.1 should be evaluated by ventilator when adjusting the depth of sedation to promote lung-protective ventilation.