- Background In previous studies ketamine was reported to improve survival and decrease serum interleukin-6 (IL-6) concentration after sepsis alone and after burn injury followed by sepsis. The aim of this study was to determine whether ketamine alters survival and/or IL-6 after hemorrhagic shock alone or hemorrhagic shock followed by sepsis. Materials and methods Rats were subjected to hemorrhagic shock with or without subsequent Gram-negative bacterial sepsis and were either treated with ketamine 5 mg/kg or were not treated. Blood was sampled for IL-6 determination prior to hemorrhage, at the completion of resuscitation, and at 6 and 30 h later. Mortality was recorded for 7 days following hemorrhage or hemorrhage + sepsis. Results After hemorrhage + sepsis the time to median mortality was significantly later in the ketamine-treated group (36 h) than in the control group (12 h). At 12 h the survival rate of the ketamine-treated group (100%) was significantly higher than in the control group (55%). There were no significant differences between groups with respect to IL-6 or 7-day survival after either hemorrhage + sepsis or hemorrhage alone. Conclusion Ketamine improved 12 h survival and delayed mortality after hemorrhage + sepsis without significantly altering IL-6, and did not alter survival or IL-6 after hemorrhage alone.