Table 4.

Changes in Local Pleural Pressures during Spontaneous Effort at High PEEP versus Low PEEP: Pig

PEEP	Lung Regions
	Nondependent	Dependent
Negative swing in local pleural pressures, cm H2O
High	−9.9 ± 2.8	−13.3 ± 2.3*
Low	−9.8 ± 2.9	−18.1 ± 4.0*†

Definition of abbreviation: PEEP = positive end-expiratory pressure.

All measurements recorded at Δ esophageal pressure approximately −10 cm H₂O. Data presented are mean ± SD.

^*P < 0.01 compared with pleural pressures in nondependent lung regions.

^†P < 0.01 compared with pleural pressures in dependent lung regions at high PEEP.