Effects Of Resuscitation With Different Fluids On Acute Lung Injury And Aquaporins During Uncontrolled Hemorrhagic Shock Complicated With Endotoxemia In Rats

Part 1 Effects of resuscitation with different fluids on hemodynamics and survival rates during uncontrolled hemorrhagic shock complicated with endotoxemia in ratsObjectiveTo investigate the effects of resuscitation with different fluids on hemodynamics and survival rates in a two-hit model of hemorrhagic shock followed by mimicked infection.MethodsSixty SD rats were randomly assigned to the following five groups: control group(C group,surgery,no hemorrhage,and no resuscitation),no fluid resuscitation group(NF group),lactated Ringer' s solution(LRS group),7.5%NaCl group(HS group)and colloid group(Hydroxylethyl starch130/0.4,HES group).We used three-phased uncontrolled hemorrhagic shock model in rats.Hemorrhagic shock phaseâ… began with blood withdrawal over 15 min,animals were subjected to massive hemorrhage[mean arterial pressure(MAP)= 35～40 mmHg for 60min and followed by intratracheal lipopolysaccharide 2 ml/kg(two-hit model).Then,animals were partially resuscitated with a lactate Ringers solution(a volume of 3 times the shed blood volume),a bolus dose of 4 ml/kg body weight of 7.5%NaCl(HS),or Hydroxylethyl starch(a volume equal to the shed blood volume)respectively. At hemorrhagic shock 90 min,resuscitation phaseâ…¡of 60 min began with hemostasis,return of all the blood initially shed,plus fluids. Observation phaseâ…¢was to 3.5h.After phaseâ…¢,arterial blood gas and survival rates were recorded.Results1.At the time of phaseâ… ,the mean arterial blood pressure(MAP)of four test groups were lower than those of control group(P＜0.01).Compared with the NF group,the LRS group,HS group and the HES group significantly improved MAP on any time from 80 minutes after shock to the end.Compared with the LRS groups,the HES group significantly improved MAP at 80 minutes of phaseâ… ,60 minutes of phaseâ…¡and phaseâ…¢.2.Compared with the NF and LRS groups,the HS and HES groups significantly improved the blood lactate,pH,PaO₂,HCO₃^-,BE and SaO₂(P＜0.05 or P＜0.01).3.The volume of blood loss in the HES and HS group was significantly lower than that in the LRS group(P＜0.01).4.The survival rates of the C group,NF group,LRS group,HS group and the HES group were 100%,58.3%,75 percent,91.7%and 91.7%respectively. The survival rates of HS group and HES group were higher than those of the LRS group(P＜0.05).ConclusionsThese findings showed that resuscitation with Hydroxylethyl starch and hypertonic fluids can distinctly improve the hemodynamics,reduce the volume of blood loss and increase the survival rates after severe uncontrolled hemorrhagic shock. ObjectiveTo investigate the effects of resuscitation with different fluids on acute lung injury and aquaporins(AQPs)in a two-hit model of hemorrhagic shock followed by mimicked infection.MethodsSixty SD rats were randomly assigned to the following five groups: control group(C group,surgery,no hemorrhage,and no resuscitation),no fluid resuscitation group(NF group),lactated Ringer' s solution(LRS group),7.5%NaCl group(HS group)and colloid group(Hydroxylethyl starch130/0.4,HES group).We used three-phased uncontrolled hemorrhagic shock model in rats.Hemorrhagic shock phaseâ… began with blood withdrawal over 15 min,animals were subjected to massive hemorrhage[mean arterial pressure(MAP)= 35～40 mmHg for 60min and followed by intratracheal lipopolysaccharide 2 ml/kg(two-hit model).Then,animals were partially resuscitated with a lactate Ringers solution(a volume of 2 times the shed blood volume),a bolus dose of 4 ml/kg body weight of 7.5%NaCl(HS),or Hydroxylethyl starch(a volume equal to the shed blood volume)respectively. At hemorrhagic shock 90 min,resuscitation phaseâ…¡of 60 min began with hemostasis,return of all the blood initially shed,plus fluids. Observation phaseâ…¢was to 3.5h.After phaseâ…¢,lung tissue was sampled to measure values of wet-to-dry lung weight ratio(W/D),pulmonary permeability index(PPI),BALF protein,and immunohistochemical and Reverse transcriptase polymerase chain reaction(RT-PCR)used for detection of expression of AQPland AQP5.ResultsCompared with the NF and LRS groups,the HES group significantly decreased pulmonary microvascular permeability and wet-to-dry lung weight ratio,and also attenuated hemorrhagic shock -induced decreased AQPland AQP5 expression in lung tissue,but these beneficial effects were blunted in the HS group.ConclusionsThese findings showed that the expression of AQPl and AQP5 may play an important role in abnormal fluid transportation and formation of pulmonary edema in uncontrolled hemorrhagic shock-induced ALI.Resuscitation with Hydroxylethyl starch and hypertonic fluids,especially with Hydroxylethyl starch can reduce lung tissue damage and pulmonary edema after severe uncontrolled hemorrhagic shock,which caused,in part by up-regulation the expression of AQP1 and /or AQP5.