Effect of continuous blood purification on concentrations of plasma vasoactive substances and cardiac function in endotoxic shock.

Objective: To evaluate the effect of continuous blood purification on cardiac function and plasma vasoactive substances in endotoxic shock in piglets.

Design: This was a randomized controlled trial in an animal laboratory in a tertiary care pediatric center.

Materials And Methods: Twenty-three healthy Shanghai white piglets weighing 8-14 kg were randomly assigned to one of the four groups: control group (n = 5), continuous blood purification without lipopolysaccharide infusion group (continuous blood purification, n = 6), lipopolysaccharide-induced endotoxin shock without continuous blood purification group (lipopolysaccharide, n = 6), and lipopolysaccharide-induced endotoxin shock with continuous blood purification group (continuous blood purification/lipopolysaccharide, n = 6).

Interventions: The lipopolysaccharide and continuous blood purification/lipopolysaccharide groups were injected intravenously with Escherichia coli endotoxin to induce septic shock. The continuous blood purification and continuous blood purification/lipopolysaccharide groups received continuous venovenous hemodiafiltration right after model establishment. At baseline state (T0), following the injection of lipopolysaccharide (T), 1 hr later (T1), 3 hrs later (T3), and 5 hrs later (T5) after model establishment, clinical systemic inflammatory response syndrome parameters, hemodynamic indexes, and plasma concentration of vasoactive substances were obtained. Plasma concentration of dopamine was measured by enzyme-linked immunosorbent assay (DSL Company) and endothelin-1 by enzyme-linked immunosorbent assay (R&D Company). Nitric oxide synthase activity was measured by chromatometry (Nanjing Jiancheng Bioengineering Institute, China).

Measurements And Main Results: In continuous blood purification/lipopolysaccharide group, after treatment with CPB, heart rate decreased significantly (p < .05) and pulse contour cardiac index, systematic vascular resistance index, and stroke volume index increased significantly (p < .05) when compared with lipopolysaccharide and continuous blood purification groups. After treatment with continuous blood purification, dopamine and endothelin-1 level increased and nitric oxide synthase activities decreased in continuous blood purification/lipopolysaccharide group when compared with the lipopolysaccharide group. In the continuous blood purification/lipopolysaccharide group, improvement in hemodynamic indexes was strongly correlated with increases in plasma dopamine and endothelin-1 level and decreases in nitric oxide synthase activity (r > .9, p < .05).

Conclusions: The adverse cardiovascular effects of lipopolysaccharide-induced endotoxin shock can be improved by continuous blood purification. Improvement is correlated with increases in the concentration of plasma vasoactive substances (endothelin and dopamine) and decreases in nitric oxide synthase activity.