Effect Of Continuous Blood Purification Combined With Mechanical Ventilation On Seawater Respiratory Distress Syndrome In Canine Models

ObjectiveEstablishing a stable model of seawater respiratory distress syndrome(SW-RDS) in canine,to investigate the effect of continuous blood purification combined with mechanical ventilation on SW-RDS.MethodsTen nomal hybrid dogs were randomly assigned into two groups: only mechanical ventilation group(MV group,n=5),all animals were only received mechanical ventilation after establishing model successfully;hemofiltration combined with mechanical ventilation group(HF+MV group,n=5),all annimals were received high volume hemofiltration puls mechanical ventilation after establishing model successfully. Both groups were observed for 4 hours. Recording mABP,HR,CVP and collecting arterial blood gas and collecting venous blood to measure plasma osmotic pressure at baseline,0min(model),60 min,120min,180min,240min after treatment; collecting venous blood to detect inflammatory mediators(IL-8,IL-6,TNF-α) at baseline,0min(model),120min, 240min after treatment; the lung pathology was assessed at the end of the experiment.Results1. All animals were suvival after four hous of treatment in both group..2. Partial pressure of oxygen(PaO2) and O2 saturation(SaO2) rised after four hours of treatment in both group(P < 0.05), HF+MV group were better than MV group. After 4 hours of treatment, pH,actual bicarbonate(AB),bases excess(BE) in HF+MV group were significantly better than those in MV group(P < 0.05),recovering to the baseline values.3. Mean arterial blood pressure(mABP),heat rate(HR),central venous pressure(CVP) were stable during the four hours of treatment, and compared with model, there were no significant difference after 4 hours of treatment in both group; there were no significant differernce at the same time of treatment in both group.4. Plasma osmotic pressure were stable during the four hours of treatment ,and compared with model, there were no significant difference in MV group.But in HF+MV group, osmotic pressure were significantly higher after 4 hours of treatment than those at the same time in MV group(p<0.05), and compared with model and 180min, those were higher too(p<0.01).5. Compared with those at the same time in MV group, plasma inflammatory mediators(IL-8,IL-6,TNF-α)were significantly decreased after 4 hours of treatment in HF+MV group(p<0.01); after 4 hours of treatment IL-8,TNF-αin MV group were higher than those at the same time in model( p<0.05).6. Compared with those in MV group, there were less infiltration of neutrophils, edema and injury of alveolar epithelium from pulmonary pathology.Conclusions1. High volume hemofiltration combined with mechanical ventilation could significantly improve hypoxemia and correct acidosis of seawater respiratory distress syndrome model in canines.2. High volume hemofiltration could effectly clear plasma inflammatory mediators and redundant water , improve pulmonary pathology changes.3. It seemed that high volume hemofiltration had no impact on mABP,HR and CVP of seawater respiratory distress syndrome.