Experimental gram-negative pneumonia produces a hyperdynamic septic profile.

General anesthesia (GA) and extensive surgery undertaken to reproduce a hyperdynamic septic shock syndrome (HSSS) may confound the observed effects of pure HSSS. A large animal model of HSSS without GA or surgery was created in sheep following production of a Pseudomonas pneumonia by direct bronchoscopic instillation into a dependent lobe using only light ketamine anesthesia. Cardiac output rose significantly (5.05 to 6.32 L/min) while SVR [1,421.4 to 1,000.5 dynes X s X cm(-5)] and mean BP (92.5 to 82.0 mmHg) fell in the septic animals. Systemic infection was confirmed by blood culture. This model reliably produces hyperdynamic sepsis without the confounding effects of GA or extensive surgery.