Modulating Organ Dysfunction in Experimental Septic Shock: Effects of Aminoglycosides, Antiendotoxin Measures and Endotoxin Tolerance
2011 (English)Doctoral thesis, comprehensive summary (Other academic)
Sepsis is a common diagnose in the intensive care population, burdened with a high mortality. The systemic inflammatory reaction underlying the development of septic organ dysfunction can be modeled using Gram-negative bacterial lipopolysaccharide, endotoxin. This thesis used a porcine endotoxemic experimental sepsis model to address clinical questions difficult to answer in clinical trials; furthermore a model of secondary sepsis was developed.
No additional effect on the development of renal dysfunction by tobramycin was found, indicating that a single dose of tobramycin does not further compromise renal function in inflammatory-induced acute kidney injury.
Antiendotoxin treatment had no measurable effect on TNF-α-mediated toxicity once the inflammatory cascade was activated. There was an effect on the leukocyte response that was associated with improvements in respiratory function and microcirculation, making it impossible to rule out fully the beneficial effect of this strategy. However, the effects were limited in relation to the magnitude of the endotoxin concentration reduction and the very early application of the antiendotoxin measure.
The lungs stood out compared to the other organ systems as having a threshold endotoxin dose for the protective effect of endotoxin tolerance. As to the development of circulatory and renal dysfunction, tolerance to endotoxin was evident regardless of the endotoxin pre-exposure and challenge dose.
There was a temporal variation of endotoxin tolerance that did not follow changes in plasma TNF-α concentrations and maximal tolerance was seen very early in the course. More pronounced endotoxin tolerance at the time of maximum tolerance was associated with a more marked hyperdynamic circulation, reduced oxygen consumption and thrombocytopenia eighteen hours later.
It might be of interest to use the experimental model of long-term endotoxemia followed by a second hit, which has been designed to resemble an intensive care setting, for the study of treatment effects of immunomodulating therapies in secondary sepsis.
Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis , 2011. , 81 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, ISSN 1651-6206 ; 655
Lipopolysaccharide, animal model, pig, tobramycin, endotoxin elimination, immunoparalysis, secondary sepsis
Research subject Infectious Diseases
IdentifiersURN: urn:nbn:se:uu:diva-149274ISBN: 978-91-554-8031-8 (print)OAI: oai:DiVA.org:uu-149274DiVA: diva2:404381
2011-04-29, Grönvallsalen, ing. 70, Akademiska sjukhuset, Uppsala, 13:15 (Swedish)
Frostell, Claes, professor
Sjölin, Jan, professor
Paper 3, previous title as submitted: "Compartmentalization of organ endotoxin tolerance in a porcine model of secondary sepsis"2011-04-072011-03-162012-03-02Bibliographically approved
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