Effects of hypotensive resuscitation on uncontrolled hemorrhagic shock in rats

Objective To study the effects of hypotensive resuscitation and larger volume fluid resuscitation on uncontrolled hemorrhagic shock and survival in rats with a standardized massive splenic injury model(MSI).Methods Following the MSI model,fifty Wistar rats were randomly and equally divided into five groups,group 1:sham-operated group,group 2: shock untreated group,group 3:normal MAP resuscitation group(during acute resuscitation phase MAP was kept at 80 mm Hg),group 4:Hypotensive resuscitation group(during acute resuscitation phase MAP was kept at(60±5) mm Hg),and group 5:larger volume fluid resuscitation with hypotensive resuscitation group(during acute resuscitation phase MAP was kept at(60±5) mm Hg,simultaneously infused SNP at 5 μg·kg~(-1)·min~(-1)).Results The mean survival time in group 1～5 was 180 min,73.50 min±8.04 min,114.30 min±31.33 min,146.70 min±28.07 min and 171.60 min±15.74 min respectively.Statistic significances were seen in each group(P0.05),except between group 1 and group 5(P=0.0671).The amount of bleeding in group 2～5(during acute resuscitation phase) was 3.79 ml/kg±1.39 ml/kg、17.41 ml/kg±8.88 ml/kg、8.67 ml/kg±4.59 ml/kg and 10.33 ml/kg±4.31 ml/kg respectively.The loss of blood in group 3 was significantly more than other groups(P0.05).Group 4 and 5 enhanced the blood loss significantly compared with group 2(P0.05).The histopathologic of liver and renal showed that histopathologic injury is severe in group 3 compared with group 4,and histopathologic injury is not in evidence in group 5.Conclusion Hypotensive resuscitation and adding SNP at proper dose additionally could improve tissue metabolism and prolong survival time during hypotensive resuscitation from uncontrolled hemorrhagic shock.It is a more ideal resuscitation method compared with normal blood pressure resuscitation.