Fig. 4

Lung P. aeruginosa burden as a function of tracheal secretions P. aeruginosa burden. a The linear regression equation was fitted to predict lung P. aeruginosa burden by tracheal secretions P. aeruginosa burden (log10 cfu/mL) and clustered by study groups. Regression equation control group: [lung P. aeruginosa burden (log₁₀ cfu/g) = − 3.06 + (0.85 × tracheal secretions P. aeruginosa burden (log₁₀ cfu/mL)]. N = 6, R = 0.85, R² = 0.73, Adjusted R^sqr = 0.67, p value = 0.029. Regression equation EFB + PEEP group: [lung P. aeruginosa burden (log₁₀ cfu/g) = − 3.68 + (0.94 × tracheal secretions P. aeruginosa burden (log₁₀ cfu/mL)]. N = 7, R = 0.76, R² = 0.57, Adjusted R^sqr = 0.49, p value = 0.048. Regression equation Trendelenburg group: [lung P. aeruginosa burden (log₁₀ cfu/g) = − 1.67 + (− 0.25 × tracheal secretions P. aeruginosa burden (log₁₀ cfu/mL)]. N = 7, R = 0.37, R² = 0.14, Adjusted R^sqr = 0.00, p value = 0.411. b The linear regression equation was fitted to predict lung P. aeruginosa burden by tracheal secretions P. aeruginosa burden (log10 cfu/mL) and clustered by development of ventilator-associated pneumonia (VAP). Regression equation VAP: [lung P. aeruginosa burden (log₁₀ cfu/g) = − 1.69 + (0.64 × tracheal secretions P. aeruginosa burden (log₁₀ cfu/mL)]. N = 10, R = 0.51, R² = 0.26, Adjusted R^sqr = 0.17, p value = 0.130. Regression equation no VAP: [lung P. aeruginosa burden (log₁₀ cfu/g) = 0.41 + (0.007 × tracheal secretions P. aeruginosa burden (log₁₀ cfu/mL)]. N = 10, R = 0.01, R² = 0.00, Adjusted R^sqr = 0.00, p value = 0.980. EFB + PEEP expiratory flow bias and positive end expiratory pressure group