Effect And Mechanism Of High Volume Hemofiltration (HVHF) On Oxygen Delivery In Shock Dogs Induced By Endotoxin

Objective:To research the effect and the mechanism of high volume hemofiltration (HVHF) on oxygen delivery (DO₂) in shock dogs induced by endotoxin (lipopolysaccharide,LPS).Method:Sixteen hybrid male dogs were injected LPS (650μg/kg) via central vein within 30min to establish model of endotoxin shock.All dogs were divided into two groups-control group and therapy group randomly (n=8).The dogs in therapy group were received the treatment of HVHF,while control group was just a sham treatment.HR,MAP,PAP,CVP,PAWP,CO were recorded at the point of basic,model and 1h,2h,3h,4h after HVHF.SVR,PVR were caculated. PaO₂,PaCO₂,HCO₃^-,SaO₂,SvO₂,HB were measurated respectively at the point of basic,model and 4h after HVHF. PaO₂/FiO₂,DO₂,VO₂,ERO₂ were caculated.Content of TNF-α,IL-6,IL-10 in circulation were measurated by radioimmunity at the point of model and 1h,2h,4h after HVHF.Results:1.After injecting LPS,MAP,CO,HR decreased gradually while PAP,PAWP,CVP,PVR,SVR increased gradually.When MAP fall down at 20% baseline,the model was established successfully.All parameters had very significant difference compared to baseline (P<0.01) and had no significant difference (Pï¹¥0.05) between groups.2.MAP,CO in therapy group increased and PAP decreased (P<0.01) while MAP,CO in control group decreased and PAP increased (P<0.01).MAP,CO in therapy group were significantly higher than those in control group at 3h,4h after HVHF (P<0.01) and PAP was significantly lower than that in control group at 2h,3h,4h after HVHF (P<0.01).3.PH in therapy group was stable (P>0.05) and HCO3—increased(P<0.01) after HVHF.PH,HCO3—in control group decreased at 4h (P<0.05).PH and HCO3—in therapy group were significantly higher than those in control group at 4h after HVHF(P<0.01).PaO₂ and PaO₂/FiO₂ in therapy group were increased(P<0.01) and decreased(P<0.05) in control group at 4h.There was very significant difference at the same time between groups (P<0.01).SaO₂ had the tendency to increase in therapy group and to decrease in control group after HVHF,but there was no difference in both groups(P>0.05) and no difference between groups(P>0.05) .DO₂ in therapy group was significantly higher than that in control group at 4h after HVHF(P<0.05). 4. TNF-α,IL-6,IL-10 in therapy group decreased significantly at 1h after HVHF and presented continuous decrease trend (P<0.01) while those in control group had no change compared to baseline (P>0.05). Between two groups,TNF-α,IL-6,IL-10 in therapy group at any time point were lower than those in control group significantly(P<0.01).Conclusion: HVHF can increase DO₂ in septic shock with hypodynamic state.The mechanism is that HVHF can eliminate inflammatory mediators and stabilize internal environment,then increase cardiac output and improve oxygenation.HVHF was an effective way to septic shock and offer a new approach to clinical treatment of septic shock.