TABLE 4.

Effect of prone position on EIT-related parameters at different PEEP levels.

			Baseline	PEEP = 21	PEEP = 18	PEEP = 15	PEEP = 12	PEEP = 9	PEEP = 6	PEEP = 3	PEEP = 0
GI	LOP	SP	0.40 ± 0.11	0.40 ± 0.03	0.37 ± 0.02	0.42 ± 0.09	0.40 ± 0.08	0.44 ± 0.08	0.50 ± 0.11	0.56 ± 0.16	0.64 ± 0.22
		PP	0.42 ± 0.24	0.40 ± 0.06	0.37 ± 0.02	0.43 ± 0.18	0.42 ± 0.18	0.43 ± 0.23	0.51 ± 0.28	0.50 ± 0.27	0.60 ± 0.35
	NLOP	SP	0.44 ± 0.11	0.41 ± 0.05	0.40 ± 0.05	0.43 ± 0.07	0.43 ± 0.07	0.44 ± 0.09	0.45 ± 0.11	0.47 ± 0.12	0.50 ± 0.13
		PP	0.42 ± 0.18	0.38 ± 0.01	0.44 ± 0.07	0.47 ± 0.16	0.46 ± 0.15	0.45 ± 0.17	0.48 ± 0.18	0.72 ± 0.63	0.57 ± 0.22
CoV	LOP	SP	46.0 ± 6.6	44.9 ± 8.2	44.4 ± 6.8	47.5 ± 7.1	47.1 ± 7.0	45.9 ± 7.1	44.4 ± 7.4	42.6 ± 6.5	41.7 ± 7.3
		PP	51.5 ± 6.4	51.3 ± 6.3	51.2 ± 5.4	50.2 ± 6.5	51.0 ± 5.9	52.2 ± 5.4	52.9 ± 5.3*	53.6 ± 5.2*	54.0 ± 6.3*
	NLOP	SP	48.0 ± 5.5	48.5 ± 2.8	48.1 ± 2.8	47.3 ± 4.4	47.8 ± 5.9	46.9 ± 5.7	46.1 ± 5.8	45.0 ± 6.2	44.1 ± 6.4
		PP	54.5 ± 8.6	49.0 ± 4.2	48.9 ± 4.0	50.4 ± 10.7	48.2 ± 12.1	48.7 ± 11.7	49.2 ± 11.4	49.9 ± 10.9	50.7 ± 10.5
RVD	LOP	SP	3.88 ± 1.70	1.74 ± 0.64	2.49 ± 1.52	3.02 ± 1.60	4.02 ± 2.87	4.01 ± 2.26	4.02 ± 2.37	4.01 ± 2.09	6.54 ± 5.22
		PP	3.33 ± 1.85	1.59 ± 0.60	2.54 ± 0.82	3.04 ± 1.45	2.88 ± 1.32	2.86 ± 1.40	2.81 ± 1.19	2.67 ± 1.10*	2.98 ± 1.36*
	NLOP	SP	4.55 ± 3.05	1.84 ± 1.01	1.81 ± 2.16	2.74 ± 1.25	3.24 ± 1.49	3.80 ± 1.63	3.90 ± 3.06	3.19 ± 0.93	3.78 ± 1.10
		PP	4.00 ± 2.19	1.70 ± 0.82	1.60 ± 1.03	3.59 ± 3.31	3.96 ± 3.12	4.02 ± 3.69	4.32 ± 3.40	3.92 ± 2.37	4.26 ± 2.07

PEEP, positive end-expiratory pressure; GI, global inhomogeneity index; CoV, center of ventilation; RVD, regional ventilation delay; *p < 0.05 compared with supine position.