CONTINUOUS ARTERIOVENOUS HEMOFILTRATION DOES NOT IMPROVE SURVIVAL IN A CANINE MODEL OF SEPTIC SHOCK

BACKGROUND: We examined whether or not continuous arteriovenous hemofi ltration (CAVH), in the absence of renal failure, would improve either hemodynamic abnormalities or survival in a canine model of septic sho ck. STUDY DESIGN: Escherichia coli 0111, as an intraperitoneal clot, w as surgically implanted into 21 one- to two-year-old purpose-bred beag les. The dogs were randomized to no CAVH (control group, n=7), shun CA VH (extracorporeal circulation without hemofiltration, n=7), or true C AVH (hemofiltration with removal of 600 mL/hour of ultrafiltrate, n=7) . Hemofiltration began one hour after clot implantation and continued for six hours. All dogs received antibiotics and had serial hemodynami c and laboratory evaluations. RESULTS: During the first seven hours of the study, all dogs displayed a progressive, significant decrease in mean arterial pressure, cardiac index, left ventricular ejection fract ion, and serum pH (all p<0.05). Two of seven dogs in the control group , one of seven dogs in the sham CAVH group, and one of seven dogs in t he true CAVH group survived seven days after clot implantation. True C AVH, which included fluid replacement with lactated Ringer's solution, significantly increased serum lactate and decreased serum bicarbonate levels after six hours (both p<0.05). However, pH did not differ betw een the three treatment groups (p>0.20). Continuous arteriovenous hemo filtration therapy had no significant effect on cardiovascular abnorma lities or survival. CONCLUSIONS: The results of this study suggest tha t CAVH would be unlikely to provide benefit to patients with gram-nega tive septic shock, in the absence of renal failure.