Effect Of The Application Pf High Volume Hemofiltration (HVHF) On Pulmonary Vascular Permeability In The Early Stage Of Septic Shock

ObjectiveSeptic shock is the leading cause of death in critically ill patients, and a basically important pathophysiological change in septic shock is microcirculatory dysfunction. An important pathological changes of progressive dyspnea and refractory hypoxemia are the increase of extravascular lung water which were caused by microvascular permeability increase and diffuse alveolar pulmonary interstitial exudative edema due to pulmonary capillary membrane damage. Progressive dyspnea and refractory hypoxemia are one of the reasons of the high mortality in clinical. Animal experiments and clinical studies have shown that continuous high-volume hemofiltration (HVHF) in the treatment of sepsis can relieve the damage of the inflammatory response to the body through reducing the concentration of inflammatory mediators in the blood significantly. But there is still lack of direct clinical evidence to prove the effect of the application for HVHF on pulmonary circulation permeability and extravascular lung water in septic shock patients. We applied HVHF and Pulse Indicator continues Cardiac Output (PiCCO) in the early stage of septic shock while we treat it, and recorded extravascular lung water content, pulmonary compliance, airway plateau pressure, pulmonary oxygenation index and E-selectin levels on different time. To investigate the effect of the application of HVHF on pulmonary vascular permeability and EVLW in septic shock patients and analysis the correlation between them.Methods51patients of septic shock who were applied protective lung ventilation strategy admitted in Intensive Care Unit were randomized into two groups (conventional group and HVHF group)by parallel randomized control trial method. Basic treatments including fluid resuscitation, Albumin infusion to maintain plasma albumin>30g/L, anti-infection, stress glucocorticoid, and the control of stress hyperglycemia were applied in conventional group; both HVHF and basic treatment were applied in HVHF group. In two groups, repeated hemodynamic measurements were done through PiCCO monitor at baseline(Tb) before HVHF, at24hours(T24),48hours (T48) and72hours (T72)after HVHF. Then, Pulmonary Compliance(Cst), Platform pressure (Pplat), Oxygenation index(PaO2/FiO2), Extravascular Lung Water index(EVLWI), Intrathoracic Blood Volume Index (ITBVI),cardiac index (CI), and E-selectin concentrations measured by enzyme-linked immunosorbent assay were determined at each time point were recorded in two groups.Results1. Oxygenation changes change after HVHF in patients of septic shock:Before treatment, PaO2/FiO2were no significant difference in two groups(P>0.05), but, it was increased significantly after treatment in two groups, and the PaO2/FiO2in HVHF group were higher than that in conventional group at T48and T72(t=2.732P<0.01, t=3.511P<0.01).2. changes in Pplat and Cst after HVHF in patients of septic shock:There were no significant difference in Pplat and Cst before treatment between two groups(P>0.05), but, the Pplat was decreased significantly after treatment in two groups, and compared with conventional group, it was lower in HVHF group at T48and T72(t=2.215P<0.05, t=4.266P<0.01). the Cst in HVHF group were higher than that in conventional group at T48and T72(t=2.516P<0.05, t=3.052P<0.01).3. Changes in parameters recorded by PiCCO monitor after HVHF in patients of septic shock:Before treatment, EVLWI, ITBVI, CI, SVRI, and MAP were no significant difference in two groups(P>0.05), but, EVLWI was decreased significantly after treatment in two groups, and compared with conventional group, it was lower in HVHF group at T48and T72(t=2.597P<0.05,t=2.125P<0.05). Compared with conventional group, ITBVI and SVRI were climbed and CI were declined in HVHF group, but, there were no significant difference in two groups(P>0.05).4. Changes in E-selectin concentrations after HVHF in patients of septic shock:There were no significant difference in E-selectin concentrations before treatment between two groups(P>0.05), but, E-selectin was decreased significantly after treatment in two groups, and compared with conventional group, it was lower in HVHF group at T48and T72(t=2.154P<0.05, t=3.581P<0.01).Conclusion1. HVHF can eliminate alveolar and pulmonary interstitial edema, improve oxygenation, had no effect on hemodynamics in patients of Septic shock.2. HVHF can reduce the incidence of ventilator-induced lung injury through improving lung compliance, reducing airway pressure and in patients of Septic shock.3. HVHF can improve pulmonary capillary permeability and reduce extravascular lung water through reduce the inflammatory response of the lungs, reducing the level of E-selectin effectively and reducing activation of pulmonary vascular endothelial cell.