Figure 4

Box plot of positive end-expiratory pressure (PEEP) values according to respiratory mechanics changes in the different categories. R, different values of resistance were applied (5, 10 and 20 cm H₂O/L/s) in combination with different compliance (30, 70, 120 cm H₂O/L); dotted line represents the 10% accuracy range and the hashed line the 5% accuracy range; values are provided as mean (95% CI) ± STD. Respiratory mechanics changes did not influence PEEP accuracy among categories; PEEP administration could be considered as inaccurate in the simple ETV category. No PEEP valve was available for mass-casualty and military devices.