Early hemorheological changes in a porcine model of intravenously given E. coli induced fulminant sepsis

Abstract

The pathophysiology of hemorheological and microcirculatory disturbances in septic process -mostly during the early hours-still not clarified in all the details, yet. In anesthetized pigs living E. coli (ATCC 25922 strain) was administered intravenously with an increasing concentration and the animals were observed for 8 hours. Before the intervention and in every 2 hours arterial (cannulated femoral artery) and venous (cannulated external jugular vein) blood samples were collected for hemorheological laboratory tests: blood and plasma viscosity, ESR, leukocyte anti-sedimentation rate, erythrocyte deformability (together with osmoscan parameters) and erythrocyte aggregation (using light-transmission and laser back-scattering methods) Control animals were stable over the 8-hour anesthesia, while septic animals died by the 6th hours in a fulminant sepsis. Over the experimental period, the tendency of impairment in erythrocyte deformability (together with osmotic gradient ektacytometry parameters) and the controversial decreasing of erythrocyte aggregation values (declining all aggregation index values, elongating t 1/2 ) were well detected in this porcine model during the early hours (4-6) of fulminant sepsis. The in vitro effect of these bacteria on erythrocytes' micro-rheological parameter was similar: decreasing red blood cell deformability and lowering aggregation. Further studies are needed to clarify the early micro-rheological changes of bacteremia and the developing sepsis.

The Effect of Sepsis on the Erythrocyte

“…Changes in the mechanical properties of erythrocytes during sepsis, which are manifested by increased RBC rigidity and measured by decreased RBC deformability, are clinically relevant for a number of reasons. First, decreased erythrocyte deformability develops early in rat (3–6 h) and pig (6–8 h) models of sepsis [ 3 , 56 , 57 ] and has been detected within 24 h of admission of critically ill patients [ 30 , 32 ]. Second, it may provide a means to differentiate between trauma and septic patients [ 30 ], as RBC deformability recovered in the former but not in the latter group of patients.…”

Red blood cell and platelet parameters are sepsis predictors in an Escherichia coli induced lethal porcine model

“…In the E.coli-treated group, sepsis was induced by Escherichia coli suspension (2.5 × 10 5 /mL; strain: ATCC 25922, Department of Medical Microbiology, University of Debrecen), which was intravenously administered in a continuously increasing manner: 2 mL in the first 30 minutes, then 4 mL in 30 minutes and afterwards 16 mL/hour for 2 hours. A total amount of 9.5 × 10 6 E. coli was infused within 3 hours [8,9]. In the control group the similar volume of isotonic saline solution was administered by the same protocol as in the septic group and no other intervention was applied.…”

Assessment of cerebral circulation in a porcine model of intravenously given E. coli induced fulminant sepsis

“…There are several limitations of the present study: We used a porcine model of intravenously administered E.coli suspension [20, 33]. Although this model is regarded as an endotoxicosis model rather than a classical sepsis model, it is widely accepted that it is suitable for modeling extreme clinical sepsis, such us meningococcaemia or gram-negative bacteremia in cases of granulocytopenia [34] .…”