Effects of positive end-expiratory pressure strategy in supine and prone position on lung and chest wall mechanics in acute respiratory distress syndrome

Annals of Intensive Care

Table 1 Respiratory mechanics in supine and prone position according to PEEP strategy

Variables	Supine position		Prone position		P values			N*
	PEEP/F_IO₂ table	Pes-guided strategy	PEEP/F_IO₂ table	Pes-guided strategy	Position effect	PEEP strategy effect	Position and PEEP interaction
PEEP set on ventilator (cmH₂O)	10 ± 2	12 ± 4	10 ± 2	12 ± 5	0.96	0.05	0.96	37
Paw,ee (cmH₂O)	11 ± 3	13 ± 4	11 ± 3	13 ± 5	0.47	0.05	0.91	37
Paw,ei (cmH₂O)	23 ± 4	24 ± 6	22 ± 4	24 ± 6	0.11	0.08	0.78	37
Pes,ee (cmH₂O)	9 ± 4	10 ± 5	9 ± 4	10 ± 5	0.88	0.05	0.83	37
Pes,ei (cmH₂O)	12 ± 4	14 ± 5	13 ± 4	14 ± 6	0.66	0.01	0.80	37
Pga,ee (cmH₂O)	12 ± 6	12 ± 5	18 ± 6	18 ± 7	< 0.001	0.19	0.06	31
Pga,ei (cmH₂O)	14 ± 6	14 ± 6	20 ± 6	21 ± 7	< 0.001	0.11	0.04	31
P_L,ee (cmH₂O)	2 ± 3	2 ± 2	2 ± 3	3 ± 2	0.78	0.15	0.96	37
P_L,ei (cmH₂O)	10 ± 5	11 ± 5	10 ± 5	10 ± 4	0.03	0.47	0.66	37
P_L,ei_Elastance (cmH₂O)	16 ± 5	17 ± 6	15 ± 5	15 ± 6	< 0.01	0.46	0.34	37
DPrs (cmH₂O)	12 ± 4	12 ± 4	11 ± 3	11 ± 4	< 0.001	0.88	0.65	37
DPcw (cmH₂O)	3 ± 1	3 ± 2	3 ± 1	4 ± 1	0.33	0.03	0.42	37
DP_L (cmH₂O)	9 ± 4	8 ± 4	8 ± 4	7 ± 4	< 0.001	0.34	0.38	37
Est,rs (cmH₂O/L)	34 ± 14	35 ± 14	32 ± 14	33 ± 14	0.04	0.46	0.83	37
Est,cw (cmH₂O/L)	9 ± 4	10 ± 5	10 ± 3	11 ± 4	0.22	0.01	0.30	37
Est,L (cmH₂O/L)	25 ± 15	25 ± 15	22 ± 15	22 ± 15	0.01	0.71	0.64	37
PaCO₂ (mmHg)	53 ± 16	55 ± 17	52 ± 14	52 ± 18	0.08	0.12	0.36	36
PaO₂/F_IO₂ ratio (mmHg)	143 ± 28	149 ± 31	172 ± 51	187 ± 53	< 0.001	0.03	0.17	36
EELV (mL)	1359 ± 503	1427 ± 456	1266 ± 391	1328 ± 415	0.01	0.08	0.93	37

Values are mean ± SD
PEEP positive end-expiratory pressure, Paw,ee static end-expiratory pressure of the respiratory system, Paw,ei static end-inspiratory pressure of the respiratory system, Pes,ee static end-expiratory esophageal pressure, Pes,ei static end-inspiratory esophageal pressure, Pga,ee static end-expiratory gastric pressure, Pga,ei static end-inspiratory gastric pressure, P_L,ee static end-expiratory transpulmonary pressure, P_L,ei static end-inspiratory transpulmonary pressure, P_L,ei _Elastance Paw,ei × Est,L/Est,rs, Est,rs, Est,cw, Est,L static elastance, of respiratory system, chest wall and lung, respectively, DPrs, DPcw, DPL driving pressure of respiratory system, chest wall and lung, respectively, EELV end-expiratory lung volume
*Due to incomplete data, some patients were excluded from the analysis