Commonly applied positive end-expiratory pressures do not prevent functional residual capacity decline in the setting of intra-abdominal hypertension: a pig model

Table 1 Influence of positive end-expiratory pressure on respiratory and haemodynamic data at baseline intra-abdominal pressure

PEEP, cmH₂O	5	8	5 vs 8	12	5 vs 12	15	5 vs 15
FRC, L	1.4 (0.4)	1.5 (0.5)	NS	1.7 (0.5)	0.002	1.7 (0.6)	< 0.001
PaO₂, mmHg	237 (14)	240 (19)	NS	236 (16)	NS	227 (25)	< 0.05
pPaw, cmH₂O	21 (6)	24 (5)	< 0.001	27 (5)	< 0.001	32 (5)	< 0.001
mPaw, cmH₂O	10 (1)	13 (2)	< 0.001	16 (2)	< 0.001	19 (1)	< 0.001
C dyn, ml/cmH₂O	25 (8)	25 (9)	NS	24 (9)	NS	21 (6)	< 0.001
CO, L/min	3.5 (1.0)	3.2 (1.0)	NS	2.7 (0.7)	0.009	2.5 (0.7)	0.002
DO₂, ml/min	498 (156)	459 (156)	NS	381 (112)	0.006	349 (100)	< 0.001
SvO₂, %	62 (7)	55 (11)	< 0.05	47 (13)	< 0.05	44 (17)	< 0.05
VO₂, ml/min	191 (47)	209 (70)	NS	205 (81)	NS	196 (53)	NS
MAP, mmHg	71 (19)	67 (15)	NS	60 (13)	0.025	56 (21)	0.004
APP, mmHg	69 (19)	64 (15)	NS	56 (13)	0.01	53 (21)	0.002
CVP, mmHg	8 (4)	8 (3)	NS	9 (2)	NS	10 (3)	NS
PAOP, mmHg	6 (2)	6 (2)	NS	8 (2)	0.004	9 (1)	< 0.001
HR, beats/min	79 (13)	81 (18)	NS	85 (20)	NS	89 (24)	0.026
SVR, dyn * s/cm⁵	1,389 (408)	1,404 (352)	NS	1,445 (373)	NS	1,337 (321)	NS
SV, ml	50 (21)	44 (13)	NS	37 (12)	0.002	33 (10)	< 0.001

APP, abdominal perfusion pressure; Cdyn, dynamic compliance; CO, cardiac output; CVP, central venous pressure; DO₂, oxygen delivery; FRC, functional residual capacity; HR, heart rate; MAP, mean arterial pressure; mPaw, mean airway pressure; PaO₂, arterial oxygen tension; PAOP, pulmonary artery occlusion pressure; PEEP, positive end-expiratory pressure; pPaw, peak airway pressure; SV, stroke volume; SvO₂, mixed venous oxygen saturation; SVR, systemic vascular resistance; VO₂, oxygen consumption. Mean (SD) are given. ANOVA and post hoc Student-Newman-Keuls were used for statistical testing. NS, not significant (P > 0.05).

ISSN: 1364-8535