Validation of a Pseudomonas aeruginosa porcine model of septic shock.

OBJECTIVES: To develop a standardized bacteraemic porcine model of septic shock with cardiovascular and immunological profiles similar to those observed in human clinical states.

METHODS: Sepsis was induced by an intravenous challenge of 18 anaesthetized pigs with live Pseudomonas aeruginosa. The pulmonary arterial pressure was monitored and the bacterial infusion was stopped when the systolic pulmonary arterial pressure reached 45 mmHg. Septic shock was treated with fluid resuscitation and epinephrine infusion. The haemodynamic parameters and the rate of different inflammatory cytokines were recorded during 6 h of observation.

RESULTS: The mean+/-SD cardiac output increased from 2.4+/-1.2 to 5.7+/-2.1 L/min while the mean+/-SD systemic vascular resistance index decreased from 1957+/-744 to 709+/-221 dyn/s/cm5/m2. The pharmacokinetic profile of the inflammatory cytokines was similar to the one observed in human studies.

CONCLUSIONS: The control of the systolic pulmonary arterial pressure during a P. aeruginosa infusion leads to a hyperdynamic, reproducible cardiovascular profile similar to the one observed in human septic shock. Since the immunological profile of the inflammatory cytokines is also similar to the human one, this standardized porcine model appears to be appropriate for experimental research concerning sepsis.