Experimental Study Of The Effects Of Protective Lung Ventilation Strategy Treatment On Acute Lung Injury Model Induced By Seawater Drowning In Rabbits

Acute lung injury(ALI) is a common clinical emergency.Studies at home and abroad demonstrated that the main pathological features of ALI are edematous alveoli and lung parenchyma,broken alveolar septa,fusion of alveoli,collapse of many alveoli,and alveoli irregular in size.Its main pathophysiological features are hypoxemia and instability of hemodynamics.Drowning is the second lethal factor on the sea at peace and war.Compared with other factors leading to lung injury,seawater may directly damage alveolar epithelial cells and endothelial cells,and initiate the lung inflammation which may lead to other injuries. Seawater drowning induced acute lung injury(SWD-ALI),is quite different from other common ALI,and is characterized by severe trauma,rapid progress,complicated changes and difficult treatment.The former studies showed that mechanical ventilation was the principal treatment of SWD-ALI.However,conventional mechanical ventilation(CMV),because of the shear stress between the overdistended alveoli and collapsed alveoli may worsen the lesions of SWD-ALI,often leads to ventilation associated lung injury(VALI),resulting in the high mortality of SWD-ALI.Although protective lung ventilation strategy may help to avoid the barotraumas,it is unfavorable to the recovering of collapsed alveoli.Objective:To observe the therapeutical effect and safety of lung protective strategy for on acute lung injury model induced by seawater drowning (SWD-ALI) in rabbits.Methods:Ventilation were used in various SWD-ALI rabbits models with various tidal volumes in five groups,including control group,6ml/kg group, 8ml/kg group,10ml/kg group,12ml/kg group(n=7).Blood gas analysis,pulmodynamic,hemodynamics status were monitored at various time point.Tumor necrosis factor(TNFα) and interleukin-6(IL-6) extracted from serum were measured after treatment.After 3 hours ventilation,HRCT were taken in every rabbits. Then rabbits of each groups were killed to gain lung tissues for pathology examination.Results:PaO2,dynamic pulmonary compliance significantly increased after ventilation treatment(tidal volume 6-8ml/kg),while mean air-way pressure,peak inspiratory pressure and airway plateau pressure markedly decreased.Conclusions:protective lung ventilation strategy is a effective and safety ventilation approach in SWD-ALI treatment.