Coupled plasma filtration adsorption in peritonitis-induced porcine hyperdynamic septic shock

Introduction

Extracorporeal blood purification techniques for the treatment of sepsis remain conceptually sound but are still an unresolved issue. Coupled plasma filtration adsorption (CPFA) enabling higher nonselective elimination of septic mediators represents a promising concept [1]. Its efficacy, however, has not been tested in a clinically relevant large animal model of septic shock. We therefore evaluated the biological effects of CPFA in a porcine long-term, hyperdynamic, peritonitis-induced septic shock model.

Methods

In 16 mechanically ventilated and instrumented pigs, fecal peritonitis was induced by inoculating autologue feces. Twelve hours after induction of sepsis, the pigs were randomly allocated to 10 hours of either CPFA (n = 8) or standard treatment (Control, n = 8). Before, 12, 18 and 22 hours after the induction of peritonitis, we measured, in addition to systemic and regional hemodynamics, ileal mucosal and renal cortex microvascular perfusion (OPS and laser Doppler flowmetry). Energy metabolism was determined by measuring arterial, hepatic, portal and renal venous lactate/pyruvate (L/P) ratios and hepatic venous ketone body (KBR) ratios. Plasma IL-6 and TNFα levels were also determined.

Results

All animals in both groups required noadrenaline infusion to maintain the mean arterial pressure above 70 mmHg. Neither the dose of vasopressor support nor the median time to development of arterial hypotension differed between the groups. In the control group, hyperdynamic septic shock resulted in a progressive deterioration of intestinal mucosal and renal cortex microvascular perfusion despite well-maintained regional blood flows. Altered microcirculation was paralleled by gradually increased systemic and regional L/P and KBR. Although CPFA blunted the otherwise progressive increase in plasma TNFα levels, it failed to beneficially influence sepsis-induced alterations in microvascular perfusion and energy metabolism.

Conclusion

In our experimental model, CPFA did not afford protection against septic shock-induced hemodynamic, microcirculatory and metabolic disturbances.