Effect of increased intra-abdominal pressure (IAP) on lung function in a sepsis model
(English)Manuscript (preprint) (Other academic)
We have previously shown that mechanical ventilation with positive pressure increases abdominal edema formation and causes an increase in intra-abdominal pressure (IAP) in a sepsis-like porcine model. In this study we investigated, in the same animal model effects of increase in IAP on the cardiovascular and respiratory system. Twelve pigs of Swedish country breed with a mean weight 28 kg were anesthetized and mechanically ventilated. Six animals received a continuous infusion of endotoxin and the other six served as controls. Catheters were inserted for vascular pressure recordings and cardiac output was measured by thermo-dilution. In both groups IAP was temporarily elevated to 20 mmHg by insufflation of CO2 into the abdominal cavity. Endotoxin infusion caused significant increases in pulmonary artery and central venous pressures and increase in shunt with fall in PaO2. Respiratory compliance was reduced. IAP elevation by CO2 insufflation increased these pressures as well as shunt further and caused additional decrease in compliance. Deflation of the abdomen returned vascular pressures to pre-insufflation but shunt remained increased and PaO2 was still reduced as was compliance. In control animals similar but smaller changes were seen on increase in IAP but with deflation not only vascular pressures but also shunt and PaO2 returned to normal. This suggests that in the sepsis-like condition, increased IAP causes persisting deterioration of lung function even when IAP has been normalized. We propose this to be caused by lung collapse that remains, at least for some time, after deflation.
intra-abdominal pressure, IAP, pneumoperitoneum, shunt, MIGET, sepsis
Anesthesiology and Intensive Care Physiology
Research subject Anaesthesiology and Intensive Care; Clinical Physiology
IdentifiersURN: urn:nbn:se:uu:diva-207402OAI: oai:DiVA.org:uu-207402DiVA: diva2:648017