Effect of continuous veno-venous hemodiafiltration on endotoxin-induced acute lung injury of the piglets.

Objective: To evaluate the effect of continuous veno-venous hemodialysis filtration (CVVHDF) on cardiopulmonary function and clearance of inflammatory mediators in piglets with endotoxin-induced acute lung injury.

Design: A randomized controlled trial.

Setting: An animal laboratory in a tertiary care pediatric center.

Subjects: : Eighteen piglets, weighing 6-8 kg.

Interventions: The piglets were anesthetized, ventilated, and received an intravenous infusion of 150 μg/kg of endotoxin. They were then randomly divided into three groups: control group (n = 6) received Ringer's lactate solution; the heparin group (n = 6) received heparin infusion plus Ringer's lactate solution; and the CVVHDF group (n = 6) received CVVHDF plus heparin infusion and Ringer's lactate solution.

Measurements And Main Results: Parameters measured simultaneously were: heart rate, mean arterial blood pressure, central venous pressure, pulse contour cardiac index, cardiac function index, left ventricular contractile index, and systemic vascular resistance index; extra vascular lung water index, respiratory rate, dynamic pulmonary compliance, airway resistance, Pao2/Fio2 ratio, serum tumor necrosis factor-α, and soluble tumor necrosis factor receptor. Lung tissue was obtained for pathologic lung injury scoring and wet/dry weight ratio. Endotoxin challenge decreased oxygenation and pulmonary mechanics, suppressed cardiac function, increased extravascular lung water, and elevated serum inflammatory mediators (tumor necrosis factor-α and soluble tumor necrosis factor receptor). After CVVHDF, pulmonary function and oxygenation improved (Pao2/Fio2, 291.5 ± 75.9 vs. 217.2 ± 45.4, respectively, p < .05); arterial blood pressure and cardiac function were restored (pulse contour cardiac index, 3.95 ± 0.52 L/min/m(2) vs. 2.69 ± 0.49 L/min/m(2), respectively, p < .05); extravascular lung water decreased, and serum inflammatory markers also decreased. Lung injury score improved and wet/dry weight ratio decreased.

Conclusion: Early CVVHDF has a beneficial effect on acute lung injury in piglets and is associated with a reduction in inflammatory cytokines, improving pulmonary function and hemodynamics and decreasing extravascular lung water and lung damage.