Effects of two resuscitation fluids on early lung injury in rats with traumatic-hemorrhagic shock

Objective To evaluate the effects of 7 5% hypertonic saline/6% hydroxyethy1 starch resuscitation on lung injury and neutrophil CD11b expression in rats with traumatic hemorrhagic shock.Methods 48 male SD rats were randomly divided into three groups:sham group,LRH group,and HSH group( n =16 in each).Traumatic hemorrhagic shock was induced and maintaimed MAP at 40mm Hg for 60 min,Rats were resuscitated with lactated Ringers (LR) solution at three times the shed blood volume added with 5 ml/kg weight of 6% hydroxyethyl starch in the LRH group over 60 minutes.The HSH was resuscitated with 5 ml/kg weight of 7 5% hypertonic saline with 6% hydroxyethyl starch in the HSH group for 30 minutes.At one hour or 24 hour after resuscitation,half of the animal each group were sacrificed.Lung myeloperoxidase (MPO)activity,lung water content and neutrophil CD11b were measured.Their lungs were preserved for histologic examination.Results MPO activity,lung water content,and neutrophil CD11b expression in the LRH group were significantly higher than those in the HSH group and sham group at the same time points ( P 0 05 or P 0 01);lung injury scores in the HSH group were lower than those in the LRH and sham group ( P 0 05 or P 0 01).At 1 hour after resuscitation in the LRH group,pulmonary alveolar space widened,PMNs and other inflammatory cells accumulated in and infiltrated around the pulmonary capillaries.At 24 hour after reusucitation,above changes in the LRH group were more evident,with infiltrates seen in alveolar cavities.Lung histology in the HSH group was almostly normal,and only few inflammatory cells infiltrated around the pulmonary capllaries.Conclusions Acute lung injury occurs in the early stage after resuscitation with LRH during traumatic hemorrhagic shock,and it is effectively prevented after resuscitation with HSH.The mechanism may possibly be related to the inhibition of pulmonary neutrophil accumulation and CD11b expression after HSH infusion. [