Multiple-organ failure and sepsis without bacteria. An experimental model

Multiple-organ failure is generally attributed to bacterial infection, although a correlation with positive blood cultures is not consistently found. Consequently, we studied the effects of a local nonbacterial inflammatory stimulus on distant organ functions and metabolism. Wistar rats were inoculated intraperitoneally with zymosan. Heart and ventilatory rates, oxygen consumption, and body temperature were measured. Survivors were killed at day 12 for blood analysis, weighing of organs, and microscopy. Intraperitoneal zymosan resulted in an early hyperdynamic "septic" response with a 35% mortality. After a few days, oxygen consumption decreased, serum lactate levels increased, and the function of multiple organs deteriorated, while blood cultures remained sterile. The experiment was repeated in germ-free rats with similar results but a lower mortality. We concluded that a severe inflammatory response in itself is capable of inducing multiple-organ failure with "sepsis."