Relationship between Abdominal Pressure, Pulmonary Compliance, and Cardiac Preload in a Porcine Model

Table 1

Effect of increasing intra-abdominal pressure (IAP) on pulmonary mechanics, pulmonary function, and global hemodynamics. Pplat plateau airway pressure, PIP peak inspiratory pressure, EVLWI extravascular lung water index, HR heart rate, MAP mean arterial pressure, MPAP mean pulmonary arterial pressure, SI stroke index, SVRI systemic vascular resistance index, and GEDVI global end-diastolic volume index. Data are expressed as mean ± SEM.

IAP (mmHg)	Baseline	10	20	30	Release
Pulmonary data
Pplat (cmH2O)	16±2	17±2	24±2 *	32±2 *	19±2^*,†
PIP (cmH2O)	19±1	20±2	27±2 *	34±2 *	21±2^†
EVLWI (mL/kg)	13±2	14±2	15±2	14±3	14±2
paO2/fiO2 (mmHg)	487±13	467±14	487±12	394±15	376±15
paCO2 (mmHg)	39±2	34±2	38±2	38±1	39±1
Hemodynamic data
HR (bpm)	92±5	97±4	92±4	93±4	92±4
MAP (mmHg)	93±4	91±5	98±5	104±5 *	98±5
MPAP (mmHg)	26±2	27±2	31±3 *	37±5 *	34±2^*,†
SI (mL/kg)	1.2±0.5	1.3±0.5 *	1.2±0.5	1.0±0.5^‡	1.2±0.5^†
SVRI (dynes·s/cm^5·kg)	35±4	28±4 *	34±5	41±5^‡	34±5^†
GEDVI (mL/kg)	15.5±1.9	17.0±3.1	16.6±3.0	14.9±2.7	17±3.7

For pulmonary data: *𝑃=0.025 versus baseline, ^†𝑃=0.015 versus IAP = 30.
For hemodynamic data: *𝑃=0.04 versus baseline, ^†𝑃=0.05 versus IAP = 30, ^‡𝑃=0.05 versus IAP = 10. All data without symbols indicate a 𝑃 value of >0.05.