Volume 16 Supplement 3
Regional perfusion and oxygenation of the kidney in an ovine model of severe sepsis with hypotension and kidney injury
© Calzavacca et al.; licensee BioMed Central Ltd. 2012
Published: 14 November 2012
The pathophysiology of septic acute kidney injury (AKI) is poorly understood. Renal medullary hypoxia has been proposed as a cause of AKI, but the changes in intrarenal oxygenation in hyperdynamic sepsis are unknown. Accordingly, we sought to determine the changes in regional renal perfusion and tissue oxygenation in the cortex and in the medulla in an ovine model of severe sepsis.
Mean arterial pressure (MAP), cardiac index (CI) and renal blood flow (RBF) were continuously monitored in conscious sheep. Fibre optic probes (Oxford Optronix) were used to measure tissue perfusion and oxygen partial pressure at 30-second intervals. Arterial and renal venous blood samples were collected for oximetry. After 24 hour of baseline data collection, sepsis was induced with live Escherichia coli infusion for 24 hours. Gentamycin was given to terminate sepsis. The animals were followed for a further 24 hours of recovery. Histology was performed to confirm the position of the catheter tips and to assess tissue viability around the probes. Data are mean (± standard error) of the average of the periods. One-way repeated-measures ANOVA was used and P < 0.05 considered significant.
This is the first study to measure intrarenal perfusion and oxygenation in hyperdynamic sepsis. In a conscious large animal model of septic AKI, we showed decreased medullary oxygenation, possibly due to mismatched local perfusion and oxygen consumption.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.