Does sodium pentobarbital anesthesia compromise clearance of bacteria or survival of dogs in lethal E coli shock?

Recent reports have indicated that circulating leukocytes play a prominent role in promoting survival in endotoxin and live E coli shock. Anesthesia has been reported to compromise host defense by depressing phagocytic activity. This study was designed to determine whether sodium pentobarbital would adversely affect leukocyte concentrations, E coli clearance, blood glucose concentrations, and survival of dogs in lethal E coli shock. A leukocytosis was produced in some dogs using daily sublethal intravenous injections of E coli endotoxin for 3 days. Three groups of dogs were challenged with LD100 E coli: Group A (saline-pretreated, normal leukocyte count, unanesthetized); Group B (endotoxin-pretreated, leukocytotic, anesthetized); and Group C (endotoxin-pretreated, leukocytotic, unanesthetized). Groups B and C reduced circulating E coli concentrations similarly but significantly more than Group A. All animals in Group A died, all in Group C lived, and 67% in Group B lived. The reduction in survival in Group B was probably due to the marked hemoconcentration in the anesthetized dogs which were unable to drink, rather than a compromise of their host defense. Inasmuch as phagocytic activity was similar between anesthetized and unanesthetized dogs, results suggest that barbiturate anesthesia is not deleterious to host defense.